Tissue slitting methods and systems

ABSTRACT

Methods and systems for separating an object, such as a lead, from formed tissue are provided. Specifically, a tissue slitting device is configured to engage patient formed tissue at a slitting engagement point. While the object is subjected to a first traction force, the tissue slitting device is caused to move further into the engaged tissue and slit the tissue past the point of engagement. The slitting device causes the tissue to separate along an axial direction of the length of the formed tissue and releases at least some of the force containing the object. The methods and systems are well suited for use in cardiac pacing or defibrillator lead explant procedures.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.13/828,231, filed Mar. 14, 2013, entitled “TISSUE SLITTING METHODS ANDSYSTEMS,” now U.S. Pat. No. ______, which claims the benefit of andpriority, under 35 U.S.C. § 119(e), to U.S. Provisional Application Ser.No. 61/701,521, filed Sep. 14, 2012, entitled “TISSUE SEPARATING METHODSAND SYSTEMS,” which are hereby incorporated herein by reference in theirentireties for all that they teach and for all purposes.

This application is also related to U.S. patent application Ser. No.13/828,310 filed on Mar. 14, 2013, entitled, “Tissue Slitting Methodsand Systems”; Ser. No. 13/828,383, filed on Mar. 14, 2013, entitled,“Tissue Slitting Methods and Systems”; Ser. No. 13/828,441 filed on Mar.14, 2013, entitled, “Tissue Slitting Methods and Systems”; Ser. No.13/828,638 filed on Mar. 14, 2013, entitled, “Lead Removal Sleeve”; andSer. No. 13/828,536 filed on Mar. 14, 2013, entitled, “Expandable LeadJacket”. The entire disclosures of the applications listed above arehereby incorporated herein by reference, in their entirety, for all thatthey teach and for all purposes.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to devices, methods and systemsfor separating tissue in a patient, and more specifically, to techniquesfor separating tissue attached to leads in a patient.

BACKGROUND

Cardiac pacing systems typically include a pacemaker and one or moreleads, which are placed inside the body of a patient. The pacemakerincludes a power source and circuitry configured to send timedelectrical pulses to the lead. The lead carries the electrical pulse tothe heart to initiate a heartbeat, and transmits information about theheart's electrical activity to the pacemaker. The lead can include afixation mechanism that holds the lead to the cardiac tissue. In somecases, a lead is inserted through a vein or artery (collectivelyvasculature) and guided to the heart where it is attached. In otherinstances, a lead is attached to the outside of the heart. During itstime in the body, tissue can attach to the lead in the form of lesions,adhesions or scar tissue, or tissue can encase a lead. In addition, thelead and/or tissue can become attached to the vasculature wall. Attimes, leads may be removed from patients for numerous reasons,including but not limited to, infections, lead age, and leadmalfunction. Accordingly, removal or extraction of the lead may presentassociated complications.

Current lead extraction techniques include mechanical traction,mechanical devices, and laser devices. Mechanical traction can beaccomplished by inserting a locking stylet into the hollow portion ofthe lead and then pulling the lead to remove it. An example of such alead locking device is described and illustrated in U.S. Pat. No.6,167,315 to Coe et al., which is hereby incorporated herein byreference in its entirety for all that it teaches and for all purposes.In some cases, dilating telescopic sheaths may also be used to stripaway the scar tissue adhering the lead to the body. Examples of a suchdevices and methods used to extract leads is described and illustratedin United States Patent Publication No. 2008/0154293 to Taylor, which ishereby incorporated herein by reference in its entirety for all that itteaches and for all purposes.

Dilation techniques typically involve pushing tissue away from the leadwhen the sheath is pushed longitudinally along the lead. However, thispushing technique may be difficult to implement, particularly when thelead has a tortuous path or curvature because the requisite longitudinalforces to extract the tissue from the lead in under these circumstancesincrease. The longitudinal forces also may require heavy counter forceson the lead, which may result in lead breakage.

Some mechanical sheaths have proposed trigger mechanisms for extending ablade from a sheath. At least some of these devices, however, involvecomplicated activation mechanisms and may not be well suited fornegotiating the tortuous paths that exist in certain vascular orphysiological environments.

Laser devices typically employ laser energy to cut the scar tissue awayfrom the lead thus allowing for removal. Examples of such laser devicesand systems are described and illustrated in U.S. Pat. Nos. 5,383,199and 5,824,026 and 5,916,210 and 6,228,076 and 6,290,668 all of which arehereby incorporated herein by reference in their entirety for all thatthey teach and for all purposes.

Further complicating lead removal is the fact that in some cases, theleads may be located in, and/or attached to, the body of a patient in astructurally-weak portion of the vasculature. For instance, typicalleads in a human may pass through the innominate vein, past the superiorvena cava (“SVC”), and into the right atrium of the heart. A majority oftissue growth can occur along the SVC and other locations along theinnominate vein where the leads make contact with the vein walls.However, tissue growth can also occur at locations within a patientwhere the leads make contact with arterials or other areas of thevasculature. Certain veins and arteries, and certain areas of vein andarterial walls, can be thin which can make lead removal a complicatedand delicate process.

SUMMARY

A traditional approach to removing tissue from implanted leads is basedon the presumption that the tissue growths are adhered directly to thesurfaces of the implanted leads. As such, methods and systems have beendesigned to dislocate the connection between the tissue attached to theimplanted device and the body of a patient. Although some tissue mayremain on the lead, current methods focus on removing most of the tissuesurrounding a circumference of the lead. In other words, while tissuemay remain attached around the lead, current systems essentially corearound this tissue surrounding the circumference of a lead to free thelead along with a section of the cored tissue to create slack forremoving the lead from a patient.

Surprisingly and unexpectedly, it has been discovered that tissue growthmay not adhere directly to the implanted lead but actually form asubstantially cylindrical “tube” around the implanted substantiallycylindrical lead at a given contact area. Contrary to conventionalwisdom, the tissue growth typically does not physically adhere to thelead. For example, this tissue growth, once formed completely around alead, forms a tubular-shaped member that essentially holds the lead andresists lead removal. The tubular-shaped section of formed tissue aroundan implanted device may impart a combination of connection forces/modesthat prevent the removal of the device from a patient. For example, thetubular-shaped section of formed tissue, or tissue growth, mayconstrict, capture, and/or surround implanted leads. In some cases, thetissue growth may constrict a lead, especially if a force is applied toone end of the lead during a removal operation. In other cases, thetissue growth may capture the lead and prevent removal, by, among otherthings, being attached to the patient and the lead simultaneously.Additionally or alternatively, the tissue growth, during attempted leadremoval, may at least partially adhere to the lead in one or moresections while completely forming around the lead.

Based upon the surprising and unexpected discovery that tissue growthmay not be directly adhered to the implanted lead, alternative devicesand methods may be used to extract an object from such tissue. In otherwords, methods and devices are disclosed herein, that are capable ofexploiting the growth nature of the tissue around a lead to efficientlyextract the lead from tissue that acts to hold the lead with some typeof force. The tissue growth may form around the lead such that the leadis contained from free movement within a patient. For instance, thetissue growth may impart a clamping, or constrictive, force around thecircumference of the lead that can prevent movement of the lead withinthis constrictive tissue growth. Due to the taught and constrictivenature of the tissue around the lead, the lead may be able to be removedwithout mechanically removing or laser ablating the entire tissue regionsurrounding the lead in a 360 degree, or circumferential, fashion.Rather, initiating a cut and/or slit of the tissue along a longitudinalaxis of the lead may allow a surgeon to easily separate the lead fromthe tissue via the slit. For example, once the tissue is initially slit,a surgeon may be able to extract the lead from the tissue, by pullingthe lead with the use of a lead locking, or similar, device. This leadextraction may be made possible by the initial slit reducing therestrictive forces caused by tissue growth in a given area. Leadextraction may also be effected by moving the lead against the initialslit created to tear through the tissue growth.

The tissue growth may need to be slit or cut along an entire length oftissue growth such that the tissue growth is no longer capable ofimparting clamping, or constrictive, forces around the lead. Once thetissue growth is slit along its length, removal of the lead from thesection of tissue growth can be achieved using various lead removaltechniques, including but not limited to, traction/counter-tractionapplied to the lead and growth, lead locking devices, snares, sheathinsertion, moving the lead against the slit portion of the tissue, andthe like.

Accordingly, there is a need for a device, method and/or system such asa device that includes a tissue slitting or cutting edge thatfacilitates slitting a length of formed tissue surrounding a lead, andoptionally a method and system capable of removing the lead from theformed tissue that captures at least a portion of an implanted lead.

In an embodiment, a tissue slitting apparatus is provided comprising: ashaft, wherein the shaft is flexible, the shaft having a proximal and adistal end, and wherein the shaft includes an inner lumen running fromthe proximal to the distal end to receive at least one of an implantedobject and mechanical traction device; and a tissue slitting tipdisposed adjacent to the distal end of the shaft, wherein the tissueslitting tip is configured to separate a tissue growth along a side anda length of the tissue growth, and wherein the tissue slitting apparatusseparates a first, but not a second, portion of the tissue growth arounda circumference of the implanted object.

In another embodiment, a method is provided comprising: separating onlya portion of a tissue growth at least substantially surrounding animplanted object in a patient; and thereafter removing the implantedobject from the tissue growth. In one embodiment, the separating andthereafter removing steps may comprise the sub-steps: attaching amechanical traction device to the implanted object; inserting themechanical traction device into a tissue slitting apparatus, the tissueslitting apparatus further comprising: a flexible shaft, wherein theflexible shaft has a proximal and a distal end; an internal lumen,wherein the internal lumen is configured to allow at least one of animplanted object and mechanical traction device to pass therethrough;and a tissue slitting tip operatively connected to the distal end of theflexible shaft; applying a mechanical traction force to the mechanicaltraction device; indexing the tissue slitting apparatus to an engagementarea of the tissue growth in contact with the implanted object; andmoving the tissue slitting tip into the tissue growth, such that thetissue growth is separated from the implanted object at least at theengagement area with the tissue slitting tip.

In yet another embodiment, a system to remove tissue from a vascularlumen is provided, the system comprising: a lead locking device forlocking onto a lead within the vascular lumen; a flexible shaftcomprising: a proximal end; a distal end comprising a sharp leading edgecapable of cutting tissue; and an internal lumen configured to allow atleast one lead to pass therethrough, wherein the lead locking deviceholds the lead while the sharp leading edge cuts tissue surrounding atleast a portion of the lead.

The method can include the steps of cutting only a portion of a tissuegrowth at least substantially surrounding an implanted object in apatient and thereafter removing the implanted object. In embodimentsdisclosed herein, the tissue growth may be subjected to a slittingaction about a partial (i.e., not complete) periphery of an internaldiameter of the tissue growth. In some embodiments, the tissue growthportion cut can be no more than about 50% of a perimeter of the tissuegrowth adjacent to and surrounding, substantially or completely, theimplanted object at any point along an encased length of the implantedobject.

The tissue slitting edge may include sharpened area, point, or blade, ina static fixed and/or dynamically deployable configuration. Additionallyor alternatively, the tissue slitting edge may utilize grindingmechanisms to cause a slit in the formed tissue. Additionally oralternatively, the tissue slitting edge may utilize emitted energy, suchas light, thermal energy, electromagnetic energy, and/or high-pressurefluid emission to cause a slit in the formed tissue. The tissue slittingedge can be an energy device, such as a power sheath, which typicallyapplies a form of energy at the sheath tip to cut the scar tissue awayfrom the lead thus allowing for removal. As the sheath is pushed overthe lead and comes to an area of attachment, the operator can turn onthe sheath's energy source to heat or vaporize scar tissue, forming thedesired slit. One of these specialized sheaths uses electrocautery,similar to what is used to cut through tissue in surgery. Another sheathhas one or more tiny lasers at its tip or edge. When activated, thelasers vaporize water molecules in scar tissue within 1 mm, forming thedesired slit or cut. Additionally or alternatively, dilating telescopicsheaths or inflatable balloons having a longitudinally positioned tissueslitting edge can be expanded, thereby deploying the tissue slittingedge to form the desired slit.

Accordingly, slitting devices (e.g., in the form of knife-edges, blades,planers, lasers and other electromagnetic radiation emitters,high-pressure fluid, grinders, sanders, drills, RF devices, ultrasonicdevices, and the like) can be configured in various combinations andmethods by which formed tissue can be removed from an implanted leadsubjected to any combination of connection modes via the formed tissue.

Removal of the formed tissue, or tissue growth, from a lead may beeffected by creating a slit, or cut, along a length of the tissuegrowth. By slitting the formed tissue along an axial portion, or length,of the tissue connected to the surgically implanted device or surgicalimplant, it is anticipated that the connection to the implanted leadwill be severely weakened. In many cases, the tissue slitting device mayallow the implanted lead to essentially peel away from the tissuepreviously surrounding the implanted lead, thereby releasing it fromcontainment. These and other needs are addressed by the various aspects,embodiments, and/or configurations of the present disclosure. Also,while the disclosure is presented in terms of exemplary embodiments, itshould be appreciated that individual aspects of the disclosure can beseparately claimed.

The tissue slitting device includes a flexible shaft having a proximalend, a distal end, and an internal lumen having an internal diameterconfigured to allow a lead, lead locking device, and/or other implanteddevice to pass through it. The device may also include a tissue slittingtip operatively coupled with the distal end of the flexible shaft. Ascan be appreciated, the slitting of formed tissue can be performed by atleast one of cutting, drilling, slicing, stripping, chopping, sanding,grinding, planing, abrasion, high-pressure fluid, laser ablation, andcombinations thereof. It is anticipated that the tissue slitting devicemay be oriented within a patient via use of the flexible shaft andmonitor, or a catheter-based system. In some cases, the tissue slittingdevice may be positioned toward the center of the vasculature, and/orproximal to a non-traumatic leading edge, such that any sharp, orworking, edge is caused to contact tissue growth and not contact thevasculature.

Among other things, the slitting section of the tissue slitting devicemay be biased against a lead/object via spring force. Additionally oralternatively, the tissue slitting device may include a flexible portionconfigured to allow the tissue slitting device to move as directedwithin a patient.

The phrases “at least one”, “one or more”, and “and/or” are open-endedexpressions that are both conjunctive and disjunctive in operation. Forexample, each of the expressions “at least one of A, B and C”, “at leastone of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B,or C” and “A, B, and/or C” means A alone, B alone, C alone, A and Btogether, A and C together, B and C together, or A, B and C together.When each one of A, B, and C in the above expressions refers to anelement, such as X, Y, and Z, or class of elements, such as X₁-X_(n),Y₁-Y_(m), and Z₁-Z₀, the phrase is intended to refer to a single elementselected from X, Y, and Z, a combination of elements selected from thesame class (e.g., X₁ and X₂) as well as a combination of elementsselected from two or more classes (e.g., Y₁ and Z₀).

The term “a” or “an” entity refers to one or more of that entity. Assuch, the terms “a” (or “an”), “one or more” and “at least one” can beused interchangeably herein. It is also to be noted that the terms“comprising”, “including”, and “having” can be used interchangeably.

“Electromagnetic radiation” (EM radiation or EMR) is a form of energyemitted and/or absorbed by charged particles, which exhibits wave-likebehavior as it travels through space. EMR has both electric and magneticfield components, which stand in a fixed ratio of intensity to eachother, and which oscillate in phase perpendicular to each other andperpendicular to the direction of energy and wave propagation. EMradiation is commonly classified by wavelength into radio, microwave,infrared, the visible spectrum perceived as visible light, ultraviolet,X-rays, and gamma rays. “Radiation” includes both EM radiation andstatic electric and magnetic and near fields.

A “lead” is a conductive structure, typically an electrically insulatedcoiled wire. The electrically conductive material can be any conductivematerial, with metals and intermetallic alloys common. The outer sheathof insulative material is biocompatible and biostable (e.g.,non-dissolving in the body) and generally includes organic materialssuch as polyurethane and polyimide. Lead types include, by way ofnon-limiting example, epicardial and endocardial leads. Leads arecommonly implanted into a body percutaneously or surgically.

A “surgical implant” is a medical device manufactured to replace amissing biological structure, support, stimulate, or treat a damagedbiological structure, or enhance, stimulate, or treat an existingbiological structure. Medical implants are man-made devices, in contrastto a transplant, which is a transplanted biomedical tissue. In somecases implants contain electronics, including, without limitation,artificial pacemaker, defibrillator, electrodes, and cochlear implants.Some implants are bioactive, including, without limitation, subcutaneousdrug delivery devices in the form of implantable pills or drug-elutingstents.

The term “means” as used herein shall be given its broadest possibleinterpretation in accordance with 35 U.S.C., Section 112, Paragraph 6.Accordingly, a claim incorporating the term “means” shall cover allstructures, materials, or acts set forth herein, and all of theequivalents thereof. Further, the structures, materials or acts and theequivalents thereof shall include all those described in the summary ofthe invention, brief description of the drawings, detailed description,abstract, and claims themselves.

It should be understood that every maximum numerical limitation giventhroughout this disclosure is deemed to include each and every lowernumerical limitation as an alternative, as if such lower numericallimitations were expressly written herein. Every minimum numericallimitation given throughout this disclosure is deemed to include eachand every higher numerical limitation as an alternative, as if suchhigher numerical limitations were expressly written herein. Everynumerical range given throughout this disclosure is deemed to includeeach and every narrower numerical range that falls within such broadernumerical range, as if such narrower numerical ranges were all expresslywritten herein.

The preceding is a simplified summary of the disclosure to provide anunderstanding of some aspects of the disclosure. This summary is neitheran extensive nor exhaustive overview of the disclosure and its variousaspects, embodiments, and configurations. It is intended neither toidentify key or critical elements of the disclosure nor to delineate thescope of the disclosure but to present selected concepts of thedisclosure in a simplified form as an introduction to the more detaileddescription presented below. As will be appreciated, other aspects,embodiments, and configurations of the disclosure are possibleutilizing, alone or in combination, one or more of the features setforth above or described in detail below

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated into and form a part of thespecification to illustrate several examples of the present disclosure.These drawings, together with the description, explain the principles ofthe disclosure. The drawings simply illustrate preferred and alternativeexamples of how the disclosure can be made and used and are not to beconstrued as limiting the disclosure to only the illustrated anddescribed examples. Further features and advantages will become apparentfrom the following, more detailed, description of the various aspects,embodiments, and configurations of the disclosure, as illustrated by thedrawings referenced below.

FIG. 1 shows an exemplary patient vasculature in section with implantedlead and multiple locations of tissue growth in accordance with someembodiments of the present disclosure;

FIG. 2A shows a detail section view of a patient vasculature andimplanted lead subjected to a traction force in a first path inaccordance with some embodiments of the present disclosure;

FIG. 2B shows a detail section view of a patient vasculature andimplanted lead subjected to a traction force in second path inaccordance with some embodiments of the present disclosure;

FIG. 2C shows a detail section view of a patient vasculature andimplanted lead subjected to a traction force in third path in accordancewith some embodiments of the present disclosure;

FIG. 3 shows a section view of a curved area of vasculature with tissuegrowth formed around an implanted lead in accordance with embodiments ofthe present disclosure;

FIG. 4 shows a cross-sectional view of the curved area of vasculature ofFIG. 3 taken along line A-A;

FIG. 5A shows a cross-sectional view of an area of vasculature with atissue slitting device introduced in accordance with embodiments of thepresent disclosure;

FIG. 5B shows a cross-sectional view of an area of vasculature with atissue slitting device engaging formed tissue in accordance withembodiments of the present disclosure;

FIG. 5C shows a cross-sectional view of an area of vasculature with atissue slitting device slitting formed tissue in accordance withembodiments of the present disclosure;

FIG. 6A shows a section view of a curved area of vasculature with atissue slitting device first introduced in accordance with embodimentsof the present disclosure;

FIG. 6B shows a section view of a curved area of vasculature with atissue slitting device in a first slitting position in accordance withembodiments of the present disclosure;

FIG. 6C shows a section view of a curved area of vasculature with atissue slitting device in a second slitting position in accordance withembodiments of the present disclosure;

FIG. 6D shows a section view of a curved area of vasculature with atissue slitting device in a third slitting position in accordance withembodiments of the present disclosure;

FIG. 7A shows a section view of a tissue slitting device in accordancewith embodiments of the present disclosure;

FIG. 7B shows a perspective view of the tissue slitting device of FIG.7A;

FIG. 8 shows a perspective view of a tissue slitting device inaccordance with embodiments of the present disclosure;

FIG. 9A shows a plan view of a tissue slitting device in accordance withembodiments of the present disclosure;

FIG. 9B shows an end view of a tissue slitting device in accordance withembodiments of the present disclosure;

FIG. 10 shows a first embodiment of a tissue slitting device inside anarea of vasculature having formed tissue surrounding an implanted leadin accordance with embodiments of the present disclosure;

FIG. 11 shows a second embodiment of a tissue slitting device inside anarea of vasculature having formed tissue surrounding an implanted leadin accordance with embodiments of the present disclosure;

FIG. 12 shows a third embodiment of a tissue slitting device inside anarea of vasculature having formed tissue surrounding an implanted leadin accordance with embodiments of the present disclosure;

FIG. 13 shows a fourth embodiment of a tissue slitting device inside anarea of vasculature having formed tissue surrounding an implanted leadin accordance with embodiments of the present disclosure;

FIG. 14A shows a first configuration of a fifth embodiment of a tissueslitting device inside an area of vasculature having formed tissuesurrounding an implanted lead in accordance with embodiments of thepresent disclosure;

FIG. 14B shows a second configuration of the fifth embodiment of atissue slitting device inside an area of vasculature having formedtissue surrounding an implanted lead in accordance with embodiments ofthe present disclosure;

FIG. 15A shows a first configuration of a sixth embodiment of a tissueslitting device inside an area of vasculature having formed tissuesurrounding an implanted lead in accordance with embodiments of thepresent disclosure;

FIG. 15B shows a second configuration of a sixth embodiment of a tissueslitting device inside an area of vasculature having formed tissuesurrounding an implanted lead in accordance with embodiments of thepresent disclosure;

FIG. 16 shows a seventh embodiment of a tissue slitting device inside anarea of vasculature having formed tissue surrounding an implanted leadin accordance with embodiments of the present disclosure;

FIG. 17 shows a eighth embodiment of a tissue slitting device inside anarea of vasculature having formed tissue surrounding an implanted leadin accordance with embodiments of the present disclosure;

FIG. 18 shows a ninth embodiment of a tissue slitting device inside anarea of vasculature having formed tissue surrounding an implanted leadin accordance with embodiments of the present disclosure;

FIG. 19A shows a perspective view of a tenth embodiment of a tissueslitting device in accordance with embodiments of the presentdisclosure;

FIG. 19B shows a section view of the tissue slitting device of FIG. 19A;

FIG. 20A shows a laser ablation tissue slitting apparatus including atissue slitting device utilizing laser ablation, a first laser generatoror system, a second laser generator or system, and an optical component.

FIG. 20B shows an eleventh embodiment of a tissue slitting device insidean area of vasculature having formed tissue surrounding an implantedlead in accordance with embodiments of the present disclosure;

FIG. 21 shows an end view of a twelfth embodiment of a tissue slittingdevice in accordance with embodiments of the present disclosure;

FIG. 22 shows an end view of a thirteenth embodiment of a tissueslitting device in accordance with embodiments of the presentdisclosure;

FIG. 23 shows an end view of a fourteenth embodiment of a tissueslitting device in accordance with embodiments of the presentdisclosure;

FIG. 24 shows an end view of a fifteenth embodiment of a tissue slittingdevice in accordance with embodiments of the present disclosure;

FIG. 25 shows an end view of a sixteenth embodiment of a tissue slittingdevice in accordance with embodiments of the present disclosure;

FIG. 26 shows a seventeenth embodiment of a tissue slitting deviceinside an area of vasculature having formed tissue surrounding animplanted lead in accordance with embodiments of the present disclosure;

FIG. 27 is a flow diagram depicting a tissue slitting method inaccordance with embodiments of the present disclosure; and

FIG. 28 shows an embodiment of a grinding tissue slitting device insidean area of vasculature having formed tissue surrounding an implantedlead in accordance with embodiments of the present disclosure.

It should be understood that the drawings are not necessarily to scale.In certain instances, details that are not necessary for anunderstanding of the disclosure or that render other details difficultto perceive may have been omitted. It should be understood, of course,that the disclosure is not necessarily limited to the particularembodiments illustrated herein.

DETAILED DESCRIPTION

Before any embodiments of the disclosure are explained in detail, it isto be understood that the disclosure is not limited in its applicationto the details of construction and the arrangement of components setforth in the following description or illustrated in the followingdrawings. The disclosure is capable of other embodiments and of beingpracticed or of being carried out in various ways. Also, it is to beunderstood that the phraseology and terminology used herein is for thepurpose of description and should not be regarded as limiting. The useof “including,” “comprising,” or “having” and variations thereof hereinis meant to encompass the items listed thereafter and equivalentsthereof as well as additional items.

Embodiments of the present disclosure are directed to tissue slitting orcutting devices and methods of using tissue slitting devices to removean implanted lead from within the vascular system of a patient. Amongother things, the method of removing an implanted lead from formedtissue may include causing at least a partial separation of tissue thatlies along an axial length of the implanted lead. In some embodiments,the tissue may be slit or cut along an entire length of the tissuegrowth to enable removal of the implanted lead. In other embodiments,the tissue may be slit or cut along a section of the tissue growth toallow an implanted lead to be removed from a patient.

While the phrases “tissue slitting edge” or “tissue cutting edge” areused in this disclosure, it is not limited to a blade or other cuttingsurface. These phrases are further intended to encompass any modalityfor slitting or cutting tissue, including the various modalitiesdiscussed herein. Non-limiting examples include not only a sharpenedarea, point, or blade but also an abrasive or cutting wire or fiber,atherotomes (microsurgical blades) mounted on an inflatable (cutting)balloon, a grinder, high intensity light such as produced by a laser,thermal or infrared energy, electromagnetic energy, and/or high-pressurefluid.

FIG. 1 depicts an exemplary patient 102 with an implanted lead 104running along the left innominate vein 112 past the superior vena cava(“SVC”) and connected into, or about, the right ventricle of the heart106. Along the length of the lead 104 at least one formed tissue growth108 is shown where the tissue 108 may completely surround a section ofthe lead 104. In a typical lead 104 explant procedure, the one or moreof the tissue growths 108 may act to contain the lead 104. For example,the tissue 108 may impart one or more forces (e.g., constrictive, shear,compression, and the like) on the lead 104 that may act to preventsuccessful removal of the lead 104 when subjected to a traction force120.

FIGS. 2A-C show examples of an implanted lead 104 subjected to atraction force via different paths in a patient 102 vasculature.Accordingly, the methods and/or devices disclosed in conjunction withany of the FIGS. 2A-C may equally apply to all instances disclosed.

FIG. 2A shows a detail view of a heart 106 having an implanted lead 104subjected to a traction force 120 in a first path in accordance withembodiments of the present disclosure. In some embodiments, a lead 104explant procedure may involve removing the lead from a patient 102 viaone or more paths. For example, a lead-locking, or other traction,device may be engaged with the lead 104 and then used to pull the lead104 from a patient. However, in some cases the lead 104 may be containedby a formed tissue growth 108 that resists the traction force 120applied to the lead 104. As can be appreciated, subjecting the lead 104to excessive traction forces 120 may cause a tear inside the patient 102where the tissue is attached to the vasculature. In one example, atissue growth 108 may form along a critical area of the vasculature,such as the SVC curve 116, of a patient. If this critical area is tornduring a lead 104 explant procedure, the result can be fatal to thepatient 102.

Complicating the lead 104 removal process is the fact that the tissuegrowth 108 surrounding a lead 104 may attach to a vessel in a curvedportion of the vasculature. Removal of the lead 104 from such a curvedportion of vasculature can present a challenge when introducing tissueremoval devices alone or in conjunction with traction devices. In somecases, the tissue removal devices include sharp edges, aggressive tips,or imprecise actuation mechanisms that can puncture the thin walls of apatient 102 vasculature. It is an aspect of the present disclosure toorient a tissue slitting working end adjacent to the unconnected, ortissue free, side 124 of a vessel wall. This orientation can preventpuncture and/or damage occurring to the vasculature at the tissueconnected side 128 of the vessel wall.

Referring now to FIG. 2B a detail section view of a patient vasculatureand implanted lead 104 subjected to a traction force 120 in second pathin accordance with some embodiments of the present disclosure is shown.In some instances, at least one end of the lead 104 may be directedinside a patient 102 for removal via a path within the vasculature.Direction of the lead 104 may be effected via a snaring tool,lead-locking device, traction device, combinations thereof, and thelike. As shown in FIG. 2B, the lead 104 is directed toward the generaldirection of a patient's femoral artery via the inferior vena cava. Thelead 104 may be directed in the manner shown to provide additionaltearing forces on the tissue growth 108 by the lead 104 being subjectedto a traction force 120. In one embodiment, the tissue growth 108 may beat least partially slit and the tearing forces created by pulling thelead 104 along the traction force 120 line cause the lead 104 toseparate from the tissue growth 108. In other embodiments, a tissueslitting device may be run along the lead 104 to the tissue growth 108via the femoral artery.

In some embodiments, the lead 104 may be captured and pulled such thatthe pull force causes the lead 104 to turn inside a patient 102. Thismode of capture and pulling may cause a bending at a first connectionpoint between the tissue growth 108 and the lead 104. When the tissueslitting device is engaged with the tissue growth 108, the assistivebending force provided by the traction force 120 can aid in slitting thetissue growth 108. For instance, the bending force may cause astretching of the tissue growth 108 where the lead engages with thetissue growth 108. This stretching of tissue may assist in the slittingoperation by causing tension on the fibers of the tissue growth 108that, when slit, pull away from the tissue slitting device engagementarea. As can be expected, the slitting operation may be performed in anyarea within a patient that is capable of receiving a tissue slittingdevice.

FIG. 2C shows a detail section view of a patient vasculature andimplanted lead 104 subjected to a traction force 120 in third path inaccordance with some embodiments of the present disclosure. Similar toFIGS. 2A and 2B, the lead 104 may be directed along a path in thepatient vasculature. In this case, the lead 104 may be directed towardthe general direction of a patient's jugular vein.

As can be appreciated, the path chosen for removal of a lead 104 from apatient 102 may depend on one or more of the orientation of the lead 104within a patient 102, the state of the at least one tissue growth 108,the lead removal device used, and the tissue slitting device used. Insome cases, the lead 104 (e.g., pacing, defibrillator, etc.), or otherobject, may have moved after implantation. In these scenarios, the lead104 may have to be captured via some other method. In some embodiments,a capturing tool equipped with a lasso, snare, or other lead graspingelement may need to be inserted into the patient 102. As can beexpected, the capturing tool may be inserted into the patient 102 viaany number of the veins and/or arteries that are interconnected to thelead 104 location in the vasculature. For example, the lead 104 may begrasped via a capturing tool that has been inserted through a patient'sfemoral artery and led to the point of the vasculature where the lead's104 free end may be located.

In some embodiments, rather than attach a separate mechanical tractiondevice, the capturing tool may be used to provide traction force 120during the tissue slitting operation. In accordance with embodiments ofthe present disclosure, the lead may be grasped via a capturing tool, orlead-locking device, and/or removed via some other pathway in thevasculature. In other words, the lead may be accessed via one or moreveins, arteries, chambers, biological channels, and/or other sections ofthe vasculature of a patient 102.

FIG. 3 shows a section view of a curved area of vasculature with tissuegrowth 108 formed around an implanted lead 104 in accordance withembodiments of the present disclosure. The tissue growth 108 maycompletely surround a section of the lead 104 and even be attached to avessel wall at a tissue connected side 128 of the vasculature. In somecases, the tissue growth 108 may not be adhered to at least one freeside 124 of a vessel, such that a vessel opening 126 exists where bodilyfluid may pass through the vessel unobstructed. Surprisingly andunexpectedly, it has been discovered that the tissue growth 108, beforeattempted lead extraction, is commonly at least substantially free ofand even more commonly completely free of attachment to the lead 104.

FIG. 4 shows a cross-sectional view of the curved area of vasculature ofFIG. 3 taken along line A-A. In some embodiments, reference may be madeto the tissue growth 108 forming a tube 132 (or cylindrical or sock-likestructure) around the implanted lead 104. Previous methods have beendisclosed that are directed to separating the tissue around the lead 104in the area defined by the tube 132. It is an aspect of the presentdisclosure to provide one or more methods and devices to effectivelyseparate the tissue growth 108 along a length of the lead to release thelead 104 from the containing forces of the tissue growth 108. In someembodiments, the tissue growth 108 may be slit at a portion of thetissue growth 108 where the thickness of tissue is minimal between thelead 104 and the open area 126 of the vessel.

In embodiments disclosed herein, the tissue growth 108 may be subjectedto a slitting action about a partial (i.e., not complete) periphery ofan internal diameter of the tissue growth 108. Stated another way, atany selected point along the tissue growth 108 or tube 132 the amount ofthe adjacent tissue cut or slit 130 to free the lead 104 is commonly nomore than about 50%, more commonly no more than about 25%, more commonlyno more than about 10%, and even more commonly no more than about 5% ofthe diameter of the tissue growth 108 or tube 132. The length of the cutor slit 130 in the tissue growth 108 or tube 132 is commonly at leastabout 50%, more commonly at least about 75%, more commonly at leastabout 90%, and even more commonly at least about 95% of the total lengthof the portion of the lead 104 surrounded by the tissue growth 108 ortube 132 along an actual and projected line of the cut or slit.

FIGS. 5A-C show a cross-section of a vessel where a tissue slittingdevice 504 is progressively engaged with a tissue growth 108. As shown,the tissue slitting device causes a section of the tissue growth 108 toseparate from a portion of the lead 104 allowing the forces containingthe lead 104 to be severely weakened and/or eliminated.

Referring to FIG. 5A a cross-sectional view of an area of vasculaturewith a tissue slitting device 504 introduced therein in accordance withembodiments of the present disclosure is shown. The tissue slittingdevice 504 includes a tissue slitting tip 508 that is configured toseparate tissue growth 108. In one embodiment, the tissue slitting tip508 may be oriented such that a slitting operation is performed on thethinnest section of tissue growth 108 between the lead 104 and the openarea 126 of the vessel. Orientation of the tissue slitting device 504may be achieved in operation via a fluoroscopy and/or other monitoringdevices and the use of one or more radiopaque markers on the tissueslitting device 504. Once the tissue slitting device 504 is oriented,the tissue slitting device 504 may contact the tissue growth 108 at anengagement area 510.

In any of the embodiments disclosed herein, the tissue slitting devicemay include an imaging system configured to provide an image from withinthe vasculature of a patient 102. It is anticipated that the imagingsystem may be disposed adjacent to the distal tip of the tissue slittingdevice. Examples of such imaging systems may include, but are in no waylimited to, technology incorporating Intravascular Ultrasound (“IVUS”),Optical Coherence Tomography (“OCT”), radio imaging, magnetic tracking,three-dimensional (“3D”) imaging, and other technologies that may beused to obtain an image within a patient.

FIG. 5B shows a cross-sectional view of an area of vasculature with atissue slitting device 504 engaging formed tissue 108 in accordance withembodiments of the present disclosure. As the tissue slitting device 504engages the tissue growth 108 the tissue slitting device 504, may slitthe tissue growth 108 by splitting, cutting, tearing, grinding, sanding,ablating, and/or otherwise causing a separation of tissue at theengagement area 510.

FIG. 5C shows a cross-sectional view of an area of vasculature with atissue slitting device 504 slitting formed tissue 108 in accordance withembodiments of the present disclosure. As shown in FIG. 5C, the tissuegrowth 108 is separated along a section of the lead 104 about theengagement area 510. In some embodiments, the tissue slitting device maybe subsequently removed from the tissue growth 108 by moving the lead104 in the direction of the separated tissue.

FIGS. 6A-D show a section view of a curved area of vasculature where anembodiment of a tissue slitting device 604 is progressively engaged witha tissue growth 108. As shown, the tissue slitting device 604 causes asection of the tissue growth 108 to separate from a portion of the lead104 allowing the forces containing the lead 104 to be severely weakenedand/or eliminated.

FIG. 6A shows a section view of a curved area of vasculature with atissue slitting device 604 first introduced in accordance withembodiments of the present disclosure. The tissue slitting device 604 isindexed into position via a directional force 618 adjacent to the tissuegrowth 108. The directional force 618 may be applied to the tissueslitting device 604 via one or more mechanical actuators, electricalactuators, manual positioning, and combinations thereof

In some embodiments, the tissue slitting device 604 includes a flexibleshaft having a proximal end, a distal end 612, and an internal lumen 616having an internal diameter configured to allow a lead, lead lockingdevice, and/or other implanted device to pass through it. The device mayalso include a tissue slitting tip 608 operatively attached to thedistal end 612 of the flexible shaft. As can be appreciated, theslitting of formed tissue can be performed by at least one of cutting,drilling, slicing, stripping, chopping, sanding, grinding, planing,abrasion, high-pressure fluid, laser ablation, and combinations thereof.It is anticipated that the tissue slitting device 604 may be orientedwithin a patient via use of the flexible shaft and monitor, or acatheter-based system. In some cases, the tissue slitting device 604 maybe positioned toward the center of the vasculature, and/or proximal to anon-traumatic leading edge, such that any sharp, or working, edge iscaused to contact tissue growth 108 and not contact the vasculature(e.g., the tissue connected side 128 wall and the free side 124 wall ofa vessel).

Additionally or alternatively, the tissue slitting tip 608 and effectiveslitting section of the tissue slitting device 604 may be biased againsta lead 104 via spring force. In some embodiments, the tissue slittingdevice 604 may include a flexible portion configured to allow the tissueslitting device 604 to move as directed within a patient.

FIG. 6B shows a section view of a curved area of vasculature with atissue slitting device 604 in a first slitting position in accordancewith embodiments of the present disclosure. As the tissue slittingdevice 604 is directed into the tissue growth 108, the tissue slittingtip 608 causes the tissue growth 108 to separate along the engagementarea 610. The separated tissue 614 allows the tissue slitting device 604to be further engaged with the tissue growth 108. Additionally oralternatively, the separated tissue 604, by releasing forces containingthe lead, can allow the lead 104 to be moved about the area of thetissue slitting tip 608.

FIG. 6C shows a section of a curved area of vasculature with the tissueslitting device 604 in a second slitting position in accordance withembodiments of the present disclosure. As the tissue slitting device 604is indexed in a direction 618 into the tissue growth 108 the tissueslitting device 604 separates tissue along an axial length of at leastone side of the lead 104. In some embodiments, the lead 104 may besubjected to a traction force 120 that may be opposite to the indexdirection 618 of the tissue slitting device 604. This applied tractionforce 120 may assist in pulling the lead 104 away from the tissue growth108 as the lead 104 is separated from containing tissue growth 108.

FIG. 6D shows a section view of a curved area of vasculature with atissue slitting device 604 in a third slitting position in accordancewith embodiments of the present disclosure. In general, the tissueslitting device 604 is indexed further into the tissue growth 108 suchthat the tissue growth 108 is almost completely separated from the lead104 along a length of the tissue growth 108. In some embodiments,slitting at least a portion of the tissue growth 108 may allow the lead104 to be removed in an explant procedure. For instance, the lead 104may be subjected to a traction force 120 to pull the lead 104 away fromany remaining the tissue growth 108. Additionally or alternatively, thelead 104 may be pulled against the remaining tissue growth 108 thatsurrounds the lead 104. In other embodiments, the tissue slitting device604 may be indexed along the entire length of the tissue growth 108 tocompletely separate the tissue growth 108 from encapsulating, orsurrounding, the lead 104.

Cutting Embodiments

FIGS. 7A-12 are directed to embodiments of a tissue slitting device thatinclude one or more cutting features that are configured to cut at leasta portion of a tissue growth 108 along a lead 104 implanted in a patient102. FIGS. 10-12 show embodiments of the tissue slitting device insidean area of vasculature where an implanted lead 104 is encapsulated by atissue growth 108. In addition to surrounding the lead 104 along asection, the tissue growth 108 is connected to a portion of the vesselwall.

In any of the embodiments disclosed herein the cutting surface may beguarded by a mechanical sheath. A mechanical sheath may include at leastone surface that acts to guard and/or protect a cutting surface frombeing accidentally exposed to one or more sensitive areas of thevasculature during navigation of a tissue slitting device within apatient 102. In one embodiment, a mechanical sheath may at leastpartially shroud a portion of a cutting surface with a compliantmaterial (e.g., silicone, polyurethane, rubber, polymer, combinationsthereof, and the like). It is anticipated that the compliant materialmay be compressed when subjected to an operation force. The compressionof the compliant material may subsequently expose the cutting surface ofthe tissue slitting device.

In another embodiment, the mechanical sheath may include a non-compliantmaterial (e.g., metal, carbon fiber, plastic, resin, combinationsthereof, and the like) that is configured to at least partially shroud aportion of a cutting surface. The non-compliant material mechanicalsheath may be configured to at least partially shroud the cuttingsurface via a compliant member (e.g., spring, flexure, compliantmaterial, combinations thereof, etc.) in connection with thenon-compliant member that maintains a shrouded position of thenon-compliant material mechanical sheath. Upon subjecting thenon-compliant material mechanical sheath to an operational force, theoperational force may be directed to the compliant member, whichsubsequently exposes the cutting surface from the mechanical sheath.

Referring now to FIGS. 7A and 7B a tissue slitting device 704 is shownin accordance with embodiments of the present disclosure. In someembodiments, the tissue slitting device 704 comprises an inner lumen716, at least one cutting surface, or knife-edge 708, a wedge taperedsection 720, and a tapered section transition 724. The inner lumen 716can be disposed between the proximal and distal end of the tissueslitting device 704. In some embodiments, the inner lumen 716 may beconfigured to allow a lead 104 and/or other objects to pass therethrough(e.g., a lead-locking device, fraction device, snare tool, etc.). As canbe appreciated, the tissue slitting device 704 may be indexed and/orguided along the lead 104 via the inner lumen 716 of the device 704.

The tissue slitting device 704 may be configured to engage with thetissue growth 108 in a patient 102 at a distal tip 712 of the device704. In some embodiments, the distal tip 712 of the device may beequipped with a knife-edge 708 configured to cut the tissue growth 108.Additionally, the knife-edge 708 may be configured to part the tissue asit cuts. In other words, the knife-edge 708 of the distal tip 712 mayinclude a wedge shape 720. As the knife-edge 708 is moved into thetissue growth 108, the cutting surface of the knife-edge 708 may severthe tissue while simultaneously parting it along the wedge shape 720 ofthe device 704. In some embodiments, the wedge shape 720 may cause aparting of separated tissue and bias the cutting surface of theknife-edge 708 against remaining tissue growth 108 attached to the lead104. Additionally or alternatively, the wedge shape 720 may beconfigured as a scalloped shape that can provide added strength to thestructure of the distal tip 712 of the tissue slitting device 704.

In some embodiments, the distal tip 712 of the tissue slitting device704 includes a knife-edge 708 disposed at the most distal portion of thetip 712 and a tapered wedge section 720 proximal to the knife-edge 708.The tapered wedge section 720 may be configured in one or more shapesdesigned to slope proximal from the knife-edge 708 distal end. Theproximal end point of the tapered wedge section may include a smoothsurface 724 that transitions from the tapered slope angle of the tip tothe circumferential surface of the device 704. In some embodiments, thesmooth surface 724 may include a radius joining the circumferentialsurface with the distal tip 712. The taper and/or radius may beconfigured to reduce trauma during navigation through the vasculatureand/or during the cutting of tissue.

In any of the embodiments disclosed herein, the taper associated withthe distal tip of the tissue slitting device may be configured withvarious shapes, angles, and dimensions. In one embodiment, the taper maybe arranged at an angle ranging from 10 to 50 degrees from a plane thatis coincident with at least two points on an axis running along thelumen of the tissue slitting device. As can be appreciated, the taperedsection of the distal tip of the tissue slitting device may be definedby its axial length from the distal end. In one embodiment, the axiallength of the tapered section of the distal tip may range from 0.025″ to0.500″. In another embodiment, the axial length of the tapered sectionof the distal tip may range from 0.050″ to 0.300″.

FIG. 8 shows a perspective view of a tissue slitting device 804 inaccordance with embodiments of the present disclosure. In someembodiments, the tissue slitting device 804 comprises an inner lumen816, at least one cutting surface, or knife-edge 808, a tapered section820, and a tapered section transition 824. The inner lumen 816 may beconfigured to allow a lead 104 and/or other objects to pass therethrough(e.g., a lead-locking device, traction device, snare tool, etc.). As canbe appreciated, the tissue slitting device 804 may be indexed and/orguided along the lead 104 via the inner lumen 816 of the device 804. Inone embodiment, the knife-edge 808 may at least partially surround theleading edges 828 adjacent to the knife-edge 808 at the distal portionof the tissue slitting device 804. In other embodiments, the knife-edge808 may completely surround the leading edges at the distal portion ofthe tissue slitting device 804. As can be appreciated, embodiments ofthe present disclosure anticipate including a sufficiently sharp portionof the knife-edge configured to slit tissue. For example, some leads104, or implanted devices may include dual-coils, exposed coils, and/orother undulating geometry. As such, tissue may be caused to form inand/or around the coils/geometry. It is anticipated that a tissueslitting tip, or knife-edge 808, with an extended blade portion 828disposed at least partially around its distal circumference may removethis additionally formed tissue growth 108.

FIGS. 9A and 9B show a tissue slitting device 904 showing variouscutting surface locations in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 904comprises an inner lumen 916, at least one cutting surface, orknife-edge 908, a tapered section 920, and a tapered section transition924. As shown in FIG. 9A, it is anticipated that the knife-edge 908 maybe disposed at a distal end of the tissue slitting device 904. In otherwords, the knife-edge 908 may be oriented at a leading edge of a tissueslitting device 904. In one embodiment, and as shown in FIG. 9B, theknife-edge 908 may be disposed at least partially inside the lumen 916of the tissue slitting device 904.

Additionally, tissue slitting devices disclosed herein may include atleast one fluorescing material or marker (e.g., radiopaque band, marker,and the like). In some embodiments, the radiopaque marker may bearranged about and/or adjacent to a knife-edge 908 of the tissueslitting device 904. The radiopaque marker, may assist in identifying alocation of the knife-edge 908 via a monitoring device. Examples ofradiopaque markers may include, but are in no way limited to, materialsand/or particles containing tantalum, tungsten, carbide, iridium,bismuth oxide, barium sulfate, cobalt, platinum and/or alloys andcombinations thereof. In some embodiments, the inner lumen 916 may beconfigured to allow a lead 104 and/or other objects to pass therethrough(e.g., a lead-locking device, traction device, snare tool, etc.). As canbe appreciated, the tissue slitting device 904 may be indexed and/orguided along the lead 104 via the inner lumen 916 of the device 904.Referring to FIG. 9B, a knife-edge 908 is oriented at least partiallywithin the lumen 916 of the tissue slitting device 904, which may allowthe device 904 to be routed through the vasculature of a patient 102without presenting sharp edges, cutting surfaces, or knife-edges 908toward sensitive areas. The knife-edge 908 oriented at least partiallywithin the lumen 916 of the tissue slitting device 904 may allow thecutting surface of the knife-edge 908 to be biased toward the tissuegrowth 108 in connection with the lead 104. In another embodiment, theknife-edge 908 may be configured as a blade positioned perpendicular tothe outer circumferential surface of the lead. The blade may bespring-loaded and/or arranged such that lead 104 is pushed against theblade when the tissue slitting device 904 is actuated along the axiallength of the lead 104. Additionally, the blade may be equipped with awedge 920 to peel the tissue away as it is being cut by the bladeportion. Additionally or alternatively, the angle of the blade relativeto the axis, and/or outer circumferential surface, of the lead 104 maybe configured to achieve an adequate cutting angle in the tissue growth108, such that the tissue 108 is slit in a manner to best achieve lead104 removal. That is, due to the overall size of the lumen, a smallangle itself may create a sharp leading edge sufficient to cut and slitthe tissue growth 108. The angle may also create smooth translation andslitting of the remainder of the tissue as the tissue slitting device904 traverses longitudinally along a direction of the lead 104.

Referring now to FIG. 10 , a first embodiment of a tissue slittingdevice 1004 inside an area of vasculature having tissue growth 108surrounding an implanted lead 104 is shown in accordance withembodiments of the present disclosure. In some embodiments, the tissueslitting device 1004 comprises an inner lumen 1016, at least one cuttingsurface 1008, a tapered section 1020, and a tapered section transition1024. The inner lumen 1016 may be configured to allow a lead 104 and/orother objects to pass therethrough (e.g., a lead-locking device,traction device, snare tool, etc.). As can be appreciated, the tissueslitting device 1004 may be indexed and/or guided along the lead 104 viathe inner lumen 1016 of the device 1004. In one embodiment, a cuttingsurface (e.g., a blade) 1008 may be disposed such that the cuttingsurface 1008 is tangent to an inner lumen, or opening, 1016 in thebody/sheath of the tissue slitting device 1004 (e.g., similar to aplaning blade). As can be appreciated, the cutting surface 1008 may bearranged at an angle at the leading edge of the tissue slitting device1004. The angle may be configured to present the cutting surface in thedirection of formed tissue that is distally adjacent to the tip of thetissue slitting device 1004. As the device 1004 is further engaged withthe tissue growth 108, the planing-style blade 1008 may be configured toremove a section of tissue 108 along at least one of a length and widthof a lead 104.

FIG. 11 shows a second embodiment of a tissue slitting device 1104inside an area of vasculature having tissue growth 108 surrounding animplanted lead 104 in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 1104comprises an inner lumen 1116, at least one knife-edge 1408, a wedgeand/or ramp 1122, a tapered section 1120, and a tapered sectiontransition 1124. The inner lumen 1116 may be configured to allow a lead104 and/or other objects to pass therethrough (e.g., a lead-lockingdevice, fraction device, snare tool, etc.). As can be appreciated, thetissue slitting device 1104 may be indexed and/or guided along the lead104 via the inner lumen 1116 of the device 1104. The knife-edge 1108 mayinclude a blade that is positioned tangent to the outer circumferentialsurface of the lead 104. The blade may be spring-loaded and/or arrangedsuch that the lead 104 is pushed against the blade when the tissueslitting device 1104 is actuated along the axial length of the lead 104.Additionally, the knife-edge 1108, or blade, may be equipped with awedge, or ramp, 1120 to part the tissue as it is being cut by the blade.As can be expected, the angle of the blade relative to the axis of thelead 104 may be configured to achieve an adequate stripping of tissuegrowth 108 in a specific area, such that the tissue 108 is slit at thespecific area.

In some embodiments, the knife-edge 1108 may be mechanically actuated toassist in cutting tissue growth 108. For instance, the knife-edge 1108may be configured to move along an axis defined by at least one sharpedge of the knife-edge 1108. Actuation of the knife-edge 1108 may beachieved via a mechanism operatively connected to the knife-edge 1108that can move the blade from one direction along the axis defined by atleast one sharp edge to the opposite direction along the axis defined bythe at least one sharp edge. This oscillating movement may be made at asub-ultrasonic frequency. Additionally or alternatively, the oscillatingblade may move at an ultrasonic frequency. In one embodiment, thefrequency of oscillation of the knife-edge 1108 may be adjusted to suitpreferences of the operator.

In another embodiment, the knife-edge 1108 may be configured to movealong an axis that is perpendicular to an axis created by the at leastone sharp edge of the knife-edge 1108. In other words, the knife-edge1108 may be configured to move from a proximal position to a distalposition along the axis of the tissue slitting device 1104. As can beappreciated, the movement of the knife-edge 1108 may be actuated torepetitively move from the proximal position to the distal position andback to the proximal position. This oscillating movement may be made ata sub-ultrasonic frequency. Additionally or alternatively, theoscillating blade may move at an ultrasonic frequency. In oneembodiment, the frequency of oscillation of the knife-edge 1108 may beadjusted to suit preferences of the operator.

FIG. 12 shows a third embodiment of a tissue slitting device 1204 insidean area of vasculature having formed tissue growth 108 surrounding animplanted lead 104 in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 1204comprises an inner lumen 1216, at least one cutting surface 1208, atapered section 1220, a tapered section transition 1224, and a tissuetension taper 1222. The inner lumen 1216 may be configured to allow alead 104 and/or other objects to pass therethrough (e.g., a lead-lockingdevice, fraction device, snare tool, etc.). As can be appreciated, thetissue slitting device 1204 may be indexed and/or guided along the lead104 via the inner lumen 1216 of the device 1204. In one embodiment, thecutting surface 1208 of the tissue slitting device 1204 may be orientedproximal to the leading edge 1226 of the distal tip 1212 of the tissueslitting device 1204. The cutting surface 1208 may be arranged such thatany sharp edge is concealed behind a smooth and/or dull surface. Thisarrangement can allow the tissue slitting device 1204 to be safelyrouted within a convoluted vasculature of a patient 102. Additionally oralternatively, the tapered surfaces 1220, 1222 of the leading edge 1226allows the tissue growth to be stretched as it is engaged and presentedto the cutting surface. As disclosed herein, the stretching of thetissue growth 108 fibers assists in the cutting operation performed bythe tissue slitting device 1204. Among other things, the tension placedon the tissue growth 108 fibers provide a taught area for the cuttingsurface 1208 to engage and cut along. In some embodiments, the leadingedge 1226 of the distal tip 1212 of the tissue slitting device 1204 maycomprise a non-traumatic surface. For example, the leading edge 1226 mayinclude a non-traumatic surface where at least some of the exposed sharpedges have been removed (e.g., a ball end, radiused surface, othercurved section, etc.). Additionally or alternatively, the taperedsurface 1222 may include a cutting surface. For instance, as the taperedsurface 1222 wedges into and engages a tissue growth 108, it maysimultaneously cut the tissue along the tapered surface 1222 as itstretches the fibers of the tissue growth 108.

In accordance with embodiments of the present disclosure, the knife-edge708, 808, 908, 1008, 1108, 1208 may be advanced into the tissue growth108. This advancement may be continuous or periodic. Additionally oralternatively, the knife-edge 708, 808, 908, 1008, 1108, 1208 may beactuated in a direction toward and away from the tissue such that theknife-edge 708, 808, 908, 1008, 1108, 1208 is presented to an area ofthe tissue growth 108, removed from the area, and represented to an areaof the tissue growth 108 to successively cut the tissue growth 108 overa number of movements. For example, the tissue growth 108 is cut in asimilar manner to that of an axe chopping at a tree. In any embodimentdisclosed herein, traction force may be applied to the lead 104 duringthe cutting of the tissue growth 108. Among other things, traction force120 can prevent tears, punctures, and other catastrophic failures causedby the force exerted on the tissue growth and/or adjacent vasculature bythe tissue slitting device 704, 804, 904, 1004, 1104, 1204.

It is anticipated that the knife-edge may be manufactured from amaterial with a suitable hardness for slitting tissue. In someembodiments, the knife-edge 708, 808, 908, 1008, 1108, 1208 may bemanufactured from a polymeric material with a durometer configured tocut a patient's tissue. Examples of polymeric material may include, butare not limited to, plastics, silicone, polytetrafluoroethylene(“PTFE”), polyethylene, polyurethane, polycarbonate, polypropylene,polyvinyl chloride (“PVC”), polystyrene, acetal, polyacetal, acetalresin, polyformaldehyde, and the like. In one embodiment, the knife-edge708, 808, 908, 1008, 1108, 1208 may be constructed from a crystalline oramorphous metal alloy. The knife-edge 708, 808, 908, 1008, 1108, 1208may comprise at least a portion of the distal tip of the tissue slittingdevice 704, 804, 904, 1004, 1104, 1204. As can be appreciated, theknife-edge 708, 808, 908, 1008, 1108, 1208 may comprise a metal insert.Examples of knife-edge 708, 808, 908, 1008, 1108, 1208 metals mayinclude, but are not limited to, steel, stainless steel (e.g.,austenitic type 304, 316, martensitic type 420, 17-4, etc.), aluminum,titanium, tungsten carbide, silver, platinum, copper, and combinationsthereof. In one embodiment, the metal may be hardened to, among otherthings, maintain a sharp edge during the tissue slitting process.

Additionally or alternatively, the knife-edge 708, 808, 908, 1008, 1108,1208 or cutting surface may be removably attached to the distal tip ofthe tissue slitting device 704, 804, 904, 1004, 1104, 1204. Benefits ofa removably attached knife-edge 708, 808, 908, 1008, 1108, 1208 allowfor quick replacement of cutting surfaces during lead removalprocedures. As can be appreciated, the replacement of the cuttingsurface may be initiated upon detecting that the cutting surface isdulling. In some cases the cutting surface may be replaced with adifferent style of blade. The style of blade may be configured to suit anumber of desires, including but not limited to, navigating difficultareas in a patient (e.g., using a curved blade, etc.), cuttingdifficult, dense, and/or hard tissue (e.g., using a serrated blade, ahardened blade, and combinations thereof, etc.), cutting tissue inconfined and/or low-growth areas (e.g., using a miniature blade), andeven removing the blade completely (e.g., using the tissue slittingdevice as a counter-traction sheath, etc.).

In some embodiments, the tissue slitting devices disclosed herein mayinclude at least one non-traumatic leading edge disposed at the mostdistal end of the device. The non-traumatic leading edge may include adistal end and a proximal end. Non-traumatic surfaces on the leadingedge of the device may include but are not limited to, spheroidal,ball-nose, radiused, smooth, round, and/or other shapes having a reducednumber of sharp edges. These non-traumatic surfaces may be configured toprevent accidental puncture or harmful contact with the patient 102. Thenon-traumatic leading edge may be configured to include a tapered and/ora wedge-shaped portion. In some cases the cross-sectional area of thetapered portion increases along a length of the non-traumatic leadingedge from the distal end to the proximal end of the leading edge. Aknife-edge and/or cutting surface may be disposed proximal to or alongthe tapered portion of the non-traumatic leading edge of the tissueslitting device.

The non-traumatic leading edge may be positioned to insert into an areabetween the tissue growth 108 and the implanted lead 104. In some casesthe tapered geometry and the arrangement of the tissue slitting devicetip may allow the most distal portion of the non-traumatic leading edgeto bias against the lead 104 and wedge under any surrounding tissuegrowth 108. As the non-traumatic leading edge is indexed further intothe tissue growth 108, the tissue growth is caused to stretch and pullaway from the lead 104. Once the non-traumatic leading edge is engagedwith the tissue growth 108, the cutting surface of the tissue slittingdevice may be caused to slit the tissue along a length of the tissuegrowth. As can be appreciated, the cutting surface may include but isnot limited to one or more knife-edge and/or cutting devices disclosedherein.

Actuated Slitting Embodiments

FIG. 13 shows a fourth embodiment of a tissue slitting device 1304inside an area of vasculature having formed tissue growth 108surrounding an implanted lead 104 in accordance with embodiments of thepresent disclosure. In some embodiments, the tissue slitting device 1304comprises an inner lumen 1316, at least one reciprocating cutting blade1308, a reciprocating blade actuation element 1310, a tapered section1320, and a tapered section transition 1324. The inner lumen 1316 may beconfigured to allow a lead 104 and/or other objects to pass therethrough(e.g., a lead-locking device, traction device, snare tool, etc.). As canbe appreciated, the tissue slitting device 1304 may be indexed and/orguided along the lead 104 via the inner lumen 1316 of the device 1304.In one embodiment, the knife-edge may be configured as a reciprocatingblade 1308. In other words, the knife-edge may be configured to moveback-and-forth in an axial direction 1318. This actuation may beindependent of the movement of the outer shaft of the device 1304. Thereciprocating motion of the blade 1308 may be achieved via areciprocating actuator that is operatively connected proximal to thedistal tip. The reciprocating actuator may be an electrical motor thatis located at the proximal end of the flexible shaft. In someembodiments, the reciprocating actuator may be manually operated via amechanical movement at the proximal end of the flexible shaft. In anyevent, energy from the actuator may be transferred to the blade 1308 viaan actuation element 1310. It is anticipated that the actuation element1310 may comprise one or more of a shaft, rod, bar, link, and the like,that is configured to transmit force from the proximal end of the tissueslitting device 1304 to the blade 1308.

In one embodiment, the reciprocating blade 1308 may be configured tomove a cutting surface horizontal to the central axis of the tissueslitting device. In other words, rather than reciprocating along an axisof the tissue slitting device, as previously disclosed, thereciprocating blade in this embodiment may operate across (orside-to-side) the distal tip of the tissue slitting device. Additionallyor alternatively, the actuation of the blade 1308, whether axial orside-to-side, may be provided at a frequency below 20 kHz. In someembodiments, the actuation frequency of the blade 1308 may exceed 20 kHz(e.g., ultrasonic range). In either case, it is anticipated that theactuation frequency of the blade 1308 may be adjusted higher or lower tosuit a cutting application (e.g., index speed, tissue type, operatorpreference, and the like).

In accordance with embodiments of the present disclosure, the blade1308, or other cutting surface, may be deployed from within a shaft ofthe tissue slitting device 1308. Additionally or alternatively, anytissue slitting member (e.g., cutting tip, grinding tips, laserablation, RF cutting, pressurized fluid cutters) may be shielded.Accordingly, any sharp or working members may be concealed from exposureto the patient 102 and/or vasculature, during navigation to a tissuegrowth 108 site. This concealment and/or shielding may act to preventdamage to a patient 102. As can be appreciated, any of the tissueslitting devices disclosed herein may utilize a deployable and/orshielded slitting member.

FIGS. 14A and 14B show a disk-style tissue slitting device 1404 insidean area of vasculature in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 1404comprises an inner lumen 1416, at least one disk-style cutting blade1408, a disk-style cutting blade actuation element 1410, a taperedsection 1420, and a tapered section transition 1424. The inner lumen1416 may be configured to allow a lead 104 and/or other objects to passtherethrough (e.g., a lead-locking device, traction device, snare tool,etc.). As can be appreciated, the tissue slitting device 1404 may beindexed and/or guided along the lead 104 via the inner lumen 1416 of thedevice 1404. As shown, the disk-style cutting blade 1408 can move in oneor more rotational direction 1418. In some embodiments, the disk-stylecutting blade 1408 may rotate continually in one direction, whileactuated. For example, the actuation element 1410 may be operativelyconnected to the disk-style cutting blade 1408 at a point that is off ofthe axis of revolution of the blade 1408. By moving the actuationelement 1410 axially in this example the off-axis motion could engenderrotation about a fixed axis of revolution. Alternatively, the actuationelement 1410 may be an electrical connection to a power source at theproximal end of the tissue slitting device 1404. In this example, thedisk-style cutting blade 1408 may include a motor at the distal end thatis operatively attached to the blade 1408 and is powered by a powersource connected to the electrical connection.

In other embodiments, the disk-style cutting blade 1408 may repeatedlyalternate directions of rotation (e.g., from a clockwise to acounterclockwise direction, and so forth). When the cutting blade 1408is engaged with a tissue growth 108, and actuated, the disk-stylecutting blade may cause at least a partial slit in the engaged tissuegrowth 108.

Referring to FIG. 14A, the disk-style cutting blade 1408 may be orientedsuch that the cutting surface of the blade 1408 is maintainedsubstantially parallel with the outer surface of the lead 104 duringcutting and engagement with a tissue growth 108. In some embodiments,the angle of the disk-style cutting blade 1408 may be arranged such thatan obtuse angle is formed between a plane that is coincident with thelead axis 104 and a non-cutting surface of the disk-style cutting blade1408. Orienting the disk-style cutting blade 1408 at an angle to thetissue growth 108 may assist in the cutting of at least one slit in thetissue growth 108 formed around the lead 104.

FIG. 14B shows the disk-style cutting blade 1408 oriented such that thecutting surface of the blade 1408 is maintained substantiallyperpendicular to the outer surface of the lead 104 during cutting andengagement with a tissue growth 108. In some embodiments, the disk-stylecutting blade 1408 may not be connected to a power source via theactuation element 1410. In this case, the cutting blade 1408 may be freeto rotate about a fixed axis of revolution and as such may be presentedto the tissue growth 108 and engaged further into the growth 108 tocreate a slit in the tissue 108.

FIGS. 15A and 15B show a deployable cutting element tissue slittingdevice 1504 inside an area of vasculature in accordance with embodimentsof the present disclosure. In some embodiments, the tissue slittingdevice 1504 comprises an inner lumen 1516, at least one deployablecutting element 1508, a leading edge 1526, a tapered section 1520, atapered section transition 1524, a tissue tension taper 1522, a cutout1530, a deployment element 1534 connected to an actuation element 1538,and a cutting element retaining member 1542. The inner lumen 1516 may beconfigured to allow a lead 104 and/or other objects to pass therethrough(e.g., a lead-locking device, traction device, snare tool, etc.). As canbe appreciated, the tissue slitting device 1504 may be indexed and/orguided along the lead 104 via the inner lumen 1516 of the device 1504.

In some embodiments, the tissue slitting device 1504 may include asection having a concealed blade or deployable cutting surface. Theleading edge 1526 may incorporate a tapered non-traumatic leading edgedisposed at the distal most end of the tissue slitting device 1504, aspreviously disclosed. Additionally or alternatively, one or morefeatures of the tissue slitting device 1504 may be configured to wedgein between the tissue growth 108 and the lead 104. In some embodiments,the tissue slitting device 1504 may include a slot, cutout, keyway,opening, or other volume 1530, housing a cutting surface 1508. In oneembodiment the cutting surface 1508 may be operatively attached to adeployment element 1534 that is configured to deploy and/or conceal thecutting surface 1508 upon receiving an input directing an actuation. Ascan be appreciated, the deployment element 1534 may comprise, but is notlimited to, one or more of, a balloon, a ramp, a screw, a wedge, anexpansible member, a cam-operated lever, a lever, a cam, andcombinations thereof. For example, the tissue slitting device 1504 maybe oriented into a position, such that the leading edge 1526 of thetissue slitting device 1504 engages with a tissue growth 108. Onceengaged, an operator may deploy the cutting surface 1508 of the tissueslitting device 1504 from a concealed position (see, e.g., FIG. 15A) byactuating the deployment element 1534 via the actuation element 1538.When the cutting surface 1508 is deployed (see, e.g., FIG. 15B), thetissue slitting device 1504 may be indexed further along the lead 104and into the formed tissue 108. While the cutting surface 1508 isdeployed and indexed along the lead 104, the formed tissue 108 is slitalong a length adjacent to the cutting surface 1508. This arrangementoffers the additional benefit of navigating the cutting surface 1508(and any sharp and/or hardened blade) inside a patient in a safecollapsed, retracted, concealed, and/or undeployed, state.

In one example, the cutting element 1508 may be deployed by actuating aballoon operatively connected to the cutting element 1508. In otherwords, in this example, the deployment element 1534 may comprise aballoon, while the actuation element 1538 may comprise a lumenconfigured to convey a fluid (e.g., gas or liquid) suitable to inflatethe balloon and extend the cutting element 1508. In some embodiments,the cutting element may be retained in the cutout 1530 via a retainingmember 1542. For instance, the retaining member may include a springconnected to the tissue slitting device 1504 (e.g., at the cutout 1530)and the cutting member 1508. Additionally or alternatively, theretaining member 1542 may assist in returning the cutting element 1508to a retracted, or concealed, state. In the case of a spring, theretaining member 1542 may exert a force on the cutting element 1508 toresist deployment without sufficient actuation via the deploymentelement 1534.

In another example, the cutting element 1508 may be deployed via a camelement operatively connected to the cutting element 1508. The camelement may be actuated via a rotation or other movement of theactuation element 1538 that is connected to the cam element. In thiscase, the retaining member 1542 may include a cam groove, guide,raceway, combinations thereof, or other combination of elements todirect and retain the cutting member 1508.

Grinding Embodiments

Referring to FIG. 16 , an embodiment of a tissue slitting device 1604inside an area of vasculature having formed tissue 108 surrounding animplanted lead 104 in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 1604comprises an inner lumen 1616, at least one reciprocating grinder 1608,a reciprocating grinder actuation element 1610, a tapered section 1620,and a tapered section transition 1624. The inner lumen 1616 may beconfigured to allow a lead 104 and/or other objects to pass therethrough(e.g., a lead-locking device, fraction device, snare tool, etc.). As canbe appreciated, the tissue slitting device 1604 may be indexed and/orguided along the lead 104 via the inner lumen 1616 of the device 1604.In one embodiment, the reciprocating grinder 1608 may be configured tomove back-and-forth in an axial direction 1618. This actuation may beindependent of the movement of the outer shaft of the device 1604. Thereciprocating motion of the grinder 1608 may be achieved via areciprocating actuator that is operatively connected proximal to thedistal tip. The reciprocating actuator may be an electrical motor thatis located at the proximal end of the flexible shaft. In someembodiments, the reciprocating actuator may be manually operated via amechanical movement at the proximal end of the flexible shaft connectedto the tissue slitting device 1604. In any event, energy from theactuator may be transferred to the grinder 1608 via an actuation element1610. It is anticipated that the actuation element 1610 may comprise oneor more of a shaft, rod, bar, link, and the like, that is configured totransmit force from the proximal end of the tissue slitting device 1604to the grinder 1608.

In one embodiment, the reciprocating blade 1608 may be configured tomove a grinding surface horizontal to the central axis of the tissueslitting device 1604. In other words, rather than reciprocating along anaxis of the tissue slitting device 1604, as previously disclosed, thereciprocating grinder in this embodiment may operate across (orside-to-side) the distal tip of the tissue slitting device 1604.Additionally or alternatively, the actuation of the grinder 1608,whether axial or side-to-side, may be provided at a frequency below 20kHz. In some embodiments, the actuation frequency of the grinder 1608may exceed 20 kHz (e.g., ultrasonic range). In either case, it isanticipated that the actuation frequency of the grinder 1608 may beadjusted higher or lower to suit a cutting application (e.g., indexspeed, tissue type, operator preference, and the like).

In some embodiments, the tissue slitting device 1604 may include agrinder disposed at the distal tip of the device 1604. The grinder 1608may be configured to slit the formed tissue 108 by subjecting the tissue108 to a moving abrasive surface. In one embodiment, the grinder 1608may include a grinding tip located at the distal tip of the device 1604.The grinder 1608 may include an abrasive surface disposed on at leastone surface that is caused to contact formed tissue 108 on a given sideof the lead 104. The grinder 1608 may be engaged with the tissue growth108 where the grinder 1608 emaciates the formed tissue 108 until thetissue 108 is slit at the point of contact with the grinder 1608. In anyof the embodiments disclosed herein, the grinding or abrasive surfacemay include at least one rough surface, knurl, machined/formed metal,abrasive surface, diamond deposition, and combinations thereof and thelike.

Referring to FIG. 17 , an embodiment of a tissue slitting device 1704inside an area of vasculature having formed tissue 108 surrounding animplanted lead 104 in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 1704comprises an inner lumen 1716, at least one grinding mechanism 1708comprising an abrasive element 1728 and at least one roller 1730, anactuation element 1710, a tapered section 1720, and a tapered sectiontransition 1724. The inner lumen 1716 may be configured to allow a lead104 and/or other objects to pass therethrough (e.g., a lead-lockingdevice, traction device, snare tool, etc.). As can be appreciated, thetissue slitting device 1704 may be indexed and/or guided along the lead104 via the inner lumen 1716 of the device 1704.

As shown, the grinding mechanism 1708 can move in one or more rotationaldirection 1718. In some embodiments, the grinding mechanism 1708 mayrotate continually in one direction, while actuated. For example, theactuation element 1710 may be operatively connected to the at least oneroller 1730 to turn the abrasive element 1728. By turning the at leastone roller 1730 and the abrasive element 1728 the grinding mechanism1708 may emaciate tissue it engages at the distal tip of the tissueslitting device 1704. Alternatively, the actuation element 1710 may bean electrical connection to a power source at the proximal end of thetissue slitting device 1704. In this example, the grinding mechanism1708 may include a motor at the distal end that is operatively attachedto the at least one roller 1730 and is powered by a power sourceconnected to the electrical connection.

In other embodiments, the at least one roller 1730 may repeatedlyalternate directions of rotation (e.g., from a clockwise to acounterclockwise direction, and so forth). When the abrasive element1728 is engaged with a tissue growth 108, and actuated, the abrasiveelement 1728 may cause at least a partial slit in the engaged tissuegrowth 108.

FIG. 18 shows an embodiment of a tissue slitting device 1804 inside anarea of vasculature having formed tissue 108 surrounding an implantedlead 104 in accordance with embodiments of the present disclosure. Insome embodiments, the tissue slitting device 1804 comprises an innerlumen 1816, at least one grinding wheel 1808 comprising at least oneabrasive surface 1828, an actuation element 1810, a tapered section1820, and a tapered section transition 1824. The inner lumen 1816 may beconfigured to allow a lead 104 and/or other objects to pass therethrough(e.g., a lead-locking device, traction device, snare tool, etc.). As canbe appreciated, the tissue slitting device 1804 may be indexed and/orguided along the lead 104 via the inner lumen 1816 of the device 1804.

As shown, the grinding wheel 1808 can move in one or more rotationaldirection 1818. In some embodiments, the grinding wheel 1808 may rotatecontinually in one direction, while actuated. For example, the actuationelement 1810 may be operatively connected to the at least wheel 1808 torotate the wheel 1808 about a fixed axis. As the grinding wheel 1808 isrotated it can emaciate tissue it engages at the distal tip of thetissue slitting device 1804. Alternatively, the actuation element 1810may be an electrical connection to a power source at the proximal end ofthe tissue slitting device 1804. In this example, the grinding wheel1808 may include a motor at the distal end that is operatively attachedto the grinding wheel 1808 and is powered by a power source connected tothe electrical connection.

In other embodiments, the grinding wheel 1808 may repeatedly alternatedirections of rotation (e.g., from a clockwise to a counterclockwisedirection, and so forth). When the abrasive surface 1828 is actuated andthen engaged with a tissue growth 108, the grinding wheel 1808 may causeat least a partial slit in the engaged tissue growth 108 by emaciatingcontacted tissue growth 108.

Referring to FIGS. 19A and 19B, an embodiment of an abrasive tissueslitting device is shown in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 1904comprises an inner lumen 1916, at least one grinding surface 1908 havingan exposed edge 1926 inside a lumen cutout 1930 of the distal tip 1912,a shielded lumen portion 1920, a tapered transition 1924, and atransmission shaft 1934. The inner lumen 1916 may be configured to allowa lead 104 and/or other objects to pass therethrough (e.g., alead-locking device, traction device, snare tool, etc.). As can beappreciated, the tissue slitting device 1904 may be indexed and/orguided along the lead 104 via the inner lumen 1916 of the device 1904.

In some embodiments, the tissue slitting device 1904 provides a rotatinggrinding surface 1908 to emaciate tissue growth 108 along one side ofthe lead 104. In other words, the tissue slitting device 1904 includes acutout 1930 to expose a grinding edge 1926 to the tissue growth 108. Itis anticipated that the grinding surface 1908 may be rotated and/oroperate similarly to the previously disclosed grinding embodiments. Inother words, the grinding surface 1908 may be rotated in one directioncontinuously and/or periodically, and/or in alternate directions (e.g.,clockwise and counterclockwise) continuously and/or periodically.

In one embodiment, the grinding surface may be partially covered by ashielded lumen portion 1920. The shielded lumen portion 1920 may preventcontact of the grinding surface with areas of the vasculature, or lead104, other than a section of the formed tissue 108 surrounding the lead104. As can be expected, the partial covering may present an exposedsection of the grinding surface 1908 to contact the formed tissue thatis engaged with the distal tip of the tissue slitting device 1904. Insome embodiments, the grinding surface 1908 may be angled, or disposedat an angle, in relation to the distal tip 1912 of the tissue slittingdevice 1904.

Laser Ablation Embodiments

FIG. 20A shows a laser ablation tissue slitting apparatus 2000Aincluding a tissue slitting device 2004A utilizing laser ablation, afirst laser generator or system 2006A, a second laser generator orsystem 2008A, and an optical component 2010A. FIGS. 20B-25 showembodiments of a tissue slitting device utilizing laser ablation and oneor more light guides that are configured to transmit light to ablate thetissue 108 surrounding at least a portion of the lead 104. It should benoted that the laser ablation embodiments may be used alone or incombination with any of the other embodiments set forth in thisdisclosure. That is, the laser ablation embodiments may be used inconjunction with the cutting, grinding, planing, high-pressure solution,and other embodiments discussed herein.

FIG. 20B shows an embodiment of a tissue slitting device 2004 inside anarea of vasculature having formed tissue 108 surrounding an implantedlead 104 in accordance with embodiments of the present disclosure. Insome embodiments, the tissue slitting device 2004 comprises an innerlumen 2016, a light-emitting distal end 2008, at least one light guide2010, a tapered section 2020, and a tapered section transition 2024. Theinner lumen 2016 may be configured to allow a lead 104 and/or otherobjects to pass therethrough (e.g., a lead-locking device, fractiondevice, snare tool, etc.). As can be appreciated, the tissue slittingdevice 2004 may be indexed and/or guided along the lead 104 via theinner lumen 2016 of the device 2004.

The light-emitting distal end 2008 of the tissue slitting device 2004may comprise one or more terminated light guides 2010. In oneembodiment, the one or more terminated light guides 2010 may be opticalfibers that can are arranged such that light is directed along a path2018 toward a tissue growth 108 surrounding an area of a lead 104. It isanticipated that the optical fibers can conduct laser light generated bya laser system located at the proximal end of the tissue slitting device2004. In some cases, the laser light may be generated in the 308 nMrange. Exemplary laser light may include pulsed laser light created byan XeCl Excimer laser system (for example, the first laser generator orsystem 2006A).

In accordance with one aspect of the present disclosure, the wavelengthof the laser light conducted by the optical fibers, and/or light guides2010, as disclosed herein may be adjusted to match a desired ablationenergy for various deposits and/or growths inside a patient. As can beappreciated, different deposits and/or growths may require differentlaser wavelengths for efficient ablation. These deposits may includetissue, fat, collagen, elastin, lipid accumulation, fibrotic layers,plaque, calcified layers, and the like. In one example, the wavelengthof the laser system may be selectively tuned using one or more opticalcomponents (for example, the optical component 2010A) to provide asecond laser wavelength. In other words, the one or more opticalcomponents may alter a characteristic associated with the light energyemitted by a laser source. Examples of such optical components mayinclude, but are not limited to, one or more filters, lenses, prisms,coatings, films, and deposited layers of optically transmissivematerial. In another example, a second laser system (for example, thesecond laser generator or system 2008A) may be optically coupled withthe optical fibers and/or light guides to provide the second laserwavelength. This second laser system and the corresponding secondwavelength may be activated in conjunction with the laser system.Alternatively, the second laser system and second laser wavelength maybe activated separately from the laser system.

It is an aspect of the present disclosure that the wavelength of thelaser light conducted by the optical fibers and/or light guides may beadjusted during an ablation operation. As can be appreciated, anoperator may select an appropriate wavelength of laser light as requiredto ablate various deposits. This selection may be performed withoutrequiring removal of the optical fibers and/or light guides from thepatient. In other words, a switch from one laser wavelength to anotherlaser wavelength can be performed outside of the patient at the lasersystem and/or the second laser system.

In one embodiment, the tissue slitting device 2004 may include featuresthat contact the lead 104 and allow the light-emitting distal end 2008to accept deviations in lead geometry and location. For instance, thefeatures may include a spring, band, or other elastic member that isoperatively connected to an area of the light-emitting distal end 2008.In this example, when the distal end 2008 contacts a change in lead 104geometry, the tissue growth 108, or other foreign object, the elasticmember can accommodate the change and adjust a position and/ororientation of the light-emitting distal end 2008.

In accordance with embodiments of the present disclosure, the tissueslitting device 2004 may configured to cause an ablation of tissue in agiven width and/or depth along an axial length of the lead 104. In someinstances, the light-emitting distal end 2008 may be configured tocauterize, ablate, or otherwise separate tissue growth 108 along a thinsection. For instance, the tissue slitting device 2004 may create aninitial separation of tissue as wide as the array of one or more opticalfibers. As can be appreciated, the width of the initial tissueseparation can be correlated to the arrangement and width of the one ormore light guide 2010 of the tissue slitting device 2004.

In another embodiment, the one or more light guide 2010 may direct lightat least partially inward toward the central axis of the lead 104. Theone or more light guide 2010 may be disposed to conduct at least portionof the light angularly toward the distal end of the tissue slittingdevice 2004 and/or toward the central axis of the lead 104. Statedanother way, each of the plurality of light guides 2010 includes aterminating end, and the terminating ends are disposed to emit lightenergy at an angle relative to the axis of the device 2004. As thetissue slitting device 2004 engages the tissue growth 108, the laserlight may be activated and the tissue 108 may be severed along the lineof conducted light.

FIG. 21 shows an embodiment of a tissue slitting device 2104 inaccordance with embodiments of the present disclosure. In someembodiments, the tissue slitting device 2104 comprises an inner lumen2116, a wall disposed radially outwardly relative to the inner lumen2116, a laser member 2112 comprising a light-emitting distal end 2108 atleast one light guide 2128 and a lead engagement feature 2132, and atapered section transition 2124. The inner lumen 2116 may be configuredto allow a lead 104 and/or other objects to pass therethrough (e.g., alead-locking device, traction device, snare tool, etc.). As can beappreciated, the tissue slitting device 2104 may be indexed and/orguided along the lead 104 via the inner lumen 2116 of the device 2104.

The laser member 2112 may include one or more features 2132 to engagewith an implanted lead 104. One example of such a lead engagementfeature 2132 may include an arcuate surface that is disposed on the lead104 side of the laser member 2112. As can be appreciated, the arcuatesurface of the lead engagement feature 2132 may substantially contactthe lead 104 at more than one point. This multiple-point contact mayprovide stability to the tissue slitting device 2104 as it is indexedalong the lead 104.

In some cases, a plurality of light guides 2128 may be arrangedvertically. As such, the light guides 2128 may direct laser light alonga plane that runs along, or parallel to, the lead 104 axis. Statedanother way, each of the plurality of light guides 2128 includes aterminating end, and the terminating ends are disposed to emit lightenergy parallel to the axis of the device 2104. In other words, thetissue slitting device 2104, when actuated and presented adjacent to atissue growth 108, may cause a separation of tissue in a tissue growth108 along an axial length of the growth 108.

FIG. 22 shows an embodiment of a tissue slitting device 2204 inaccordance with embodiments of the present disclosure. In someembodiments, the tissue slitting device 2204 comprises an inner lumen2216, a laser member 2212 comprising a light-emitting distal end 2208 atleast one light guide 2228 and a lead engagement feature 2232, and atapered section transition 2224. The inner lumen 2216 may be configuredto allow a lead 104 and/or other objects to pass therethrough (e.g., alead-locking device, traction device, snare tool, etc.). As can beappreciated, the tissue slitting device 2204 may be indexed and/orguided along the lead 104 via the inner lumen 2216 of the device 2204.

The laser member 2212 may include one or more features 2232 to engagewith an implanted lead 104. One example of such a lead engagementfeature 2232 may include an arcuate surface that is disposed on the lead104 side of the laser member 2212. As can be appreciated, the arcuatesurface of the lead engagement feature 2232 may substantially contactthe lead 104 at more than one point. This multiple-point contact mayprovide stability to the tissue slitting device 2204 as it is indexedalong the lead 104.

In some cases, a plurality of light guides 2228 may be arrangedhorizontally. As such, the light guides 2228 may direct laser lightalong a plane that runs along, or parallel to, the outer circumferenceof the lead 104. In other words, the tissue slitting device 2204, whenactuated and presented adjacent to a tissue growth 108, may cause aseparation of tissue in a tissue growth 108 along an axial length andwidth of the growth 108. This separation of tissue is similar to theremoval of tissue provided by the embodiment disclosed in FIG. 11 .

FIG. 23 shows a distal end view of a laser tissue slitting device 2304in accordance with embodiments of the present disclosure. In someembodiments, the tissue slitting device 2304 comprises a shaft 2324, aninner lumen 2316, and a plurality of optical fibers 2328. illustrates atube having a distal end with optical fibers included therein. The innerlumen 2316 may be configured to allow a lead 104 and/or other objects topass therethrough (e.g., a lead-locking device, fraction device, snaretool, etc.). As can be appreciated, the tissue slitting device 2304 maybe indexed and/or guided along the lead 104 via the inner lumen 2316 ofthe device 2304. The optical fibers 2328 may be used to ablate a sectionof tissue growth 108 surrounding a lead 104. Additionally oralternatively, the optical fibers 2328 may be disposed in a portion ofthe shaft 2324 or about the entire periphery of the shaft 2324.

FIGS. 24-25 show embodiments where one or more laser ablation featuresare combined with other tissue slitting embodiments as disclosed orsuggested herein.

Referring to FIG. 24 , a distal end view of a tissue slitting device2404 is shown in accordance with embodiments of the present disclosure.In some embodiments, the tissue slitting device 2404 comprises a shaft2424, an inner lumen 2416, at least one wedge feature 2420, and aplurality of optical fibers 2428. Additionally or alternatively, thetissue slitting device 2404 may include a cutting edge 2408. The innerlumen 2416 may be configured to allow a lead 104 and/or other objects topass therethrough (e.g., a lead-locking device, traction device, snaretool, etc.). As can be appreciated, the tissue slitting device 2404 maybe indexed and/or guided along the lead 104 via the inner lumen 2416 ofthe device 2404. The optical fibers 2428 may be used to ablate a sectionof tissue growth 108 surrounding a lead 104. The optical fibers 2428 maybe disposed in a portion of the shaft 2424 or about the entire peripheryof the shaft 2424. In some embodiments, when the optical fibers 2428 areincluded in only a portion of the shaft 2424, it may be preferable tobias the optical fibers 2428 adjacent to the cutting edge 2408 orcutting tip of the shaft 2424 as shown. Alternatively, it may bepreferable to include the optical fibers 2428 at a distance away fromthe cutting edge 2408 or cutting tip of the shaft 2424. In someembodiments, it may be preferable to include as many optical fibers 2428as possible within the circumference of the shaft 2424.

FIG. 25 shows a distal end view of a tissue slitting device 2504 inaccordance with embodiments of the present disclosure. In someembodiments, the tissue slitting device 2504 comprises a shaft 2524, aninner lumen 2516, at least one cutting wedge feature 2520, and aplurality of optical fibers 2528. Additionally or alternatively, thetissue slitting device 2504 may include a distal cutting edge 2508. Theinner lumen 2516 may be configured to allow a lead 104 and/or otherobjects to pass therethrough (e.g., a lead-locking device, tractiondevice, snare tool, etc.). As can be appreciated, the tissue slittingdevice 2504 may be indexed and/or guided along the lead 104 via theinner lumen 2516 of the device 2504. The optical fibers 2528 may be usedto ablate a section of tissue growth 108 surrounding a lead 104. Theoptical fibers 2528 may be disposed in a portion of the shaft 2524 orabout the entire periphery of the shaft 2524. In some embodiments, whenthe optical fibers 2528 are included in only a portion of the shaft2524, it may be preferable to bias the optical fibers 2528 adjacent tothe distal cutting edge 2508 or cutting tip of the shaft 2524 as shown.Alternatively, it may be preferable to include the optical fibers 2528at a distance away from the cutting edge 2508 or cutting tip of theshaft 2524. In some embodiments, it may be preferable to include as manyoptical fibers 2528 as possible within the circumference of the shaft2524.

Additionally or alternatively, the tissue slitting edge may utilizeother wavelengths of emitted radiation energy, such as thermal orinfrared energy, electromagnetic radiation, and/or other radiationwavelengths to slit or cut the formed tissue. The tissue slitting edgecan, for example, be an energy device, such as a power sheath (of acatheter), which typically applies a form of energy at the sheath tip tocut the scar tissue away from the lead thus allowing for removal. As thesheath is pushed over the lead and comes to an area of attachment, theoperator can turn on the sheath's energy source to heat or vaporize scartissue, forming the desired slit. One such sheath uses electrocautery,similar to what is used to cut through tissue in surgery. Another sheathhas one or more tiny energy emitters at its tip or edge. When activated,the emitted energy vaporizes water molecules in scar tissue within about1 mm, thereby forming the desired slit or cut. Additionally oralternatively, dilating telescopic sheaths or cutting balloons of acatheter having a longitudinally positioned tissue slitting edge can befully or partially expanded or inflated, thereby deploying the tissueslitting edge to form the desired slit.

In some embodiments, the distal tip of the tissue slitting device 2504may include a wedge cutting feature 2520. The wedge cutting feature 2520may comprise a blade and a wedge configured to peel the tissue away fromthe cutting edge 2508 of the tissue slitting device 2504 as it is beingcut by the cutting edge 2508 and the blade. Utilizing a combination oflaser ablation embodiments with other tissue slitting embodiments allowsfor creative solutions to various tissue growths 108. For example, thelaser light in a laser tissue slitting device 2504 may be actuated inpulses to ablate sections of difficult tissue growth 108 while the wedgecutting feature 2520 acts to cut and separate ablated and other areas ofthe tissue growth 108. As can be appreciated, various laser embodimentsand/or actuation techniques and other tissue slitting features may becombined to best suit individual tissue growth 108 in a patient 102.

It should be noted that the laser ablation embodiments, as well as theother embodiments disclosed herein, may be used alone or in combinationwith the non-traumatic leading edge, wedges, tapers, and/or other tissueslitting embodiments disclosed without limitation. Additionally oralternatively, the tissue slitting devices disclosed herein may includeat least one fluorescing material or marker (e.g., radiopaque band,marker, and the like). In some embodiments, the radiopaque marker may bearranged about and/or adjacent to a tissue cutting area (e.g., laseroptical fibers, blades, planers, electromagnetic radiation emitter, RFdevices, high-pressure fluid, grinders, sanders, drills, ultrasonicdevices, and the like) of the tissue slitting device. The radiopaquemarker, may assist in identifying a location of the tissue cutting areavia a monitoring device. Examples of radiopaque markers may include, butare in no way limited to, materials and/or particles containingtantalum, tungsten, carbide, iridium, bismuth oxide, barium sulfate,cobalt, platinum and/or alloys and combinations thereof.

High-Pressure Solution Embodiments:

FIG. 26 shows a tissue slitting device 2604 inside an area ofvasculature having tissue growth 108 surrounding an implanted lead 104in accordance with embodiments of the present disclosure. In someembodiments, the tissue slitting device 2604 comprises a shaft 2606, aninner lumen 2616, at least one fluid channel 2610, at least one nozzle2608, a tissue-side taper 2620, and an opening-side taper 2608.Additionally or alternatively, the tissue slitting device 2604 mayinclude a port opening 2630. The inner lumen 2616 may be configured toallow a lead 104 and/or other objects to pass therethrough (e.g., alead-locking device, traction device, snare tool, etc.). As can beappreciated, the tissue slitting device 2604 may be indexed and/orguided along the lead 104 via the inner lumen 2616 of the device 2604.Embodiments of the present disclosure anticipate using a solution (e.g.,NaCl, MgCl, saline, etc.) directed under pressure to remove formedtissue 108 attached to an implanted lead 104. A fluid channel 2610having a proximal end, a distal end, and an inner lumen running from theproximal end of the fluid channel 2610 to an area of the distal end ofthe tissue slitting device 2604, may be disposed substantially parallelto the shaft 2606 to contain the pressurized solution (e.g., NaCl,saline, etc.).

In some embodiments, the channel 2610 may taper in the form of a nozzle2608 at the distal end to focus fluid expelled from the channel 2610. Ascan be appreciated, the focus of the fluid out of the nozzle 2608increases the pressure of the fluid that contacts a tissue growth 108.Alternatively, a fluid channel 2610 may include a port opening 2630 thatdoes not include any taper. As such, the fluid is not focused as it isexpelled from the fluid port opening 2630. In some embodiments, thechannel 2610 may include a plurality of orifices configured to expelsaline solution. This plurality of orifices may include one or morenozzle 2608 features to control the rate of flow of the saline solution.Additionally or alternatively, the at least one orifice may be directedtoward the lead 104, formed tissue 108, or other object and/orobstruction. In one embodiment, a first orifice may be oriented at afirst angle to the lead 104 and/or formed tissue 108, and a secondorifice may be oriented at a second angle to the lead 104 and/or formedtissue 108. In another embodiment, the angle and/or shape of the nozzle2608, opening 2630, or orifices may be affected by the angle of thetissue-side taper 2620 and/or the opening-side taper 2608. Among otherthings, the orifices may be used to clear obstructions, clean the lead104 as the tissue slitting device 2604 is moved along the lead 104,and/or provide lubrication for the inner lumen 2616 of tissue slittingdevice 2604 as it is moved along a lead 104.

Additionally or alternatively, solution may be forced between the tissuegrowth 108 and the lead 104 via at least one channel 2610 associatedwith the tissue slitting device 2604. The forced solution may act toexpand and/or dilate the tissue growth 108 formed around a lead 104 orobject. In some embodiments, the dilation of the formed tissue 108created by the solution may create an opening for insertion of thedistal end of the tissue slitting device 2604.

As can be appreciated, use of the forced solution may be combined withany other device and/or method disclosed herein. In one embodiment, theforced solution may cause the formed tissue 108 to expand around thelead 104 such that the formed tissue 108 no longer applies any forces tothe lead 104. In such cases, the lead 104 may be removed from the formedtissue 108 while it is dilated.

Referring to FIG. 27 , a tissue slitting method 2700 will be describedin accordance with at least some embodiments of the present disclosure.The method 2700 starts at 2704 and begins by connecting a lead-lockingdevice or other traction device to the lead 104 (step 2708). In someembodiments, the lead-locking device may be inserted into the core of animplanted lead 104. In other embodiments, a traction device may beconnected to the lead 104 to provide traction on the lead 104. Forinstance, mechanical traction can be achieved in leads 104 by insertinga locking stylet into the lead 104 and applying a pull force onto thelead 104 via the locking stylet.

Once a traction device is attached to the lead 104, the traction devicecan be threaded through the internal, or inner, lumen of the tissueslitting device (step 2712). For example, the lead-locking device may beinserted through the lumen in an implanted lead 104 and attached to theinternal portions of the implanted lead 104, which can be at the distalportion or proximal to the distal portion of the lead 104. The tissueslitting device may be part of a catheter that rides over the externalportion of the lead 104 and lead-locking device and is configured toremove tissue along an axial length of the tissue 108 in contact withthe lead 104.

As the tissue slitting device is engaged with the lead 104, a slighttraction force may be applied to the lead 104 to allow the tissueslitting device to guide along the lead 104 (step 2716). The tissueslitting device can be moved toward the first formed tissue growth whileapplying a mechanical traction force to the lead 104 itself or through alocking stylet, or other traction device. Mechanical traction forceshould be applied with appropriate force to prevent tearing the vein orartery wall by moving the lead 104 and tissue before they are separated.In some embodiments, the tissue slitting device may be observed movinginside a patient 102 via a fluoroscope or other monitor. It isanticipated that the distal tip, or some other area, of the tissueslitting device may include a fluorescing material or marker (e.g.,radiopaque band, and the like). This fluorescing material or marker maybe used to aid in monitoring the movement of the tissue slitting devicewhen it is inside a patient.

Next, the tissue slitter is moved into contact with the formed tissuegrowth (step 2720). In some embodiments, the slitting portion of thetissue slitting device may be oriented toward the center of the vein, oraway from the vein wall connecting the lead 104 to the vein. In additionto preventing accidental puncture, trauma, or other damage to thedelicate surfaces of the vasculature this orientation of the tissueslitting device may aid in the slitting and peeling away of the tissue108 from the implanted lead 104. For example, a tissue slitting devicemay include a distal tip with a wedge and/or tapered portion proximal tothe sharp portion of the tissue slitting device. It is anticipated thatthe distal tip of the tissue slitting device may include a non-traumaticleading edge. In some cases, the non-traumatic leading edge and thetapered portion may comprise the distal tip of the tissue slittingdevice. While applying mechanical traction force, the leading portion(of the tissue slitting device) may include a sharp, cutting, ablating,or grinding portion, which may be configured to cut into the tissuegrowth 108. As the tissue slitting device traverses along the lead 104,the cutting portion of the tissue slitting device continues to separatethe formed tissue 108. Additionally the leading portion, which mayinclude a wedge and/or tapered portion, can act to cause a stretching ofthe formed tissue growth 108 at the point where it engages with thetissue slitting device. This stretching of tissue may assist in theslitting operation by causing tension on the fibers of the tissue growth108 that, when slit, pull back (or away) from the tissue slitting deviceengagement area.

Once the tissue slitting device is engaged with, and/or slitting, theformed tissue, the tissue slitting device may be actuated and movedalong the lead to further engage with the tissue growth 108 (step 2724).In some embodiments, the tissue slitting device may be indexed forward(into the tissue formation 108) continuously or periodically. In otherembodiments, the tissue slitting device may be repeatedly indexed intoand removed from the engagement area of the formed tissue growth 108. Itis anticipated that each time the tissue slitting device is indexed intothe engagement area the device can make a successively longer slit inthe formed tissue 108.

The method 2700 may be continued by determining whether other tissuegrowths exist, and if so, indexing the tissue slitting device througheach formed tissue growth 108 that is surrounding a section of theimplanted lead 104 in the vasculature (step 2728).

Once all of the formed tissue growths 108 are slit, the tissue slittingdevice may be removed from the patient 102 (step 2732). Additionally oralternatively, once the slits have been made the lead 104 may be removedby applying a pull force to the lead-locking device in the samedirection as the mechanical traction force previously applied to thelead 104. It is anticipated that any movement of the tissue slittingdevice may be accompanied by an applied mechanical traction force to thelead/lead-locking device. The method 2700 ends at step 2736.

Other Embodiments

Referring to FIG. 28 , an embodiment of an abrasive tissue slittingdevice is shown in accordance with embodiments of the presentdisclosure. In some embodiments, the tissue slitting device 2804comprises an inner lumen 2816, at least one grinding surface 2808 havingan exposed portion 2826 at least partially surrounded by a distal tipshield 2820, a tapered transition 2824, and a transmission shaft 2834.The inner lumen 2816 may be configured to allow a lead 104 and/or otherobjects to pass therethrough (e.g., a lead-locking device, tractiondevice, snare tool, etc.). As can be appreciated, the tissue slittingdevice 2804 may be indexed and/or guided along the lead 104 via theinner lumen 2816 of the device 2804.

In some embodiments, the tissue slitting device 2804 provides one ormore rotating grinding surface 2808 to emaciate tissue growth 108 alongat least one side of the lead 104. In other words, the tissue slittingdevice 2804 includes at least one opening 2830 to expose a grinding edge2826 to the tissue growth 108. It is anticipated that the grindingsurface 2808 may be rotated and/or operate similarly to the previouslydisclosed grinding embodiments. In other words, the grinding surface2808 may be rotated in one direction continuously and/or periodically,and/or in alternate directions (e.g., clockwise and counterclockwise)continuously and/or periodically. As can be appreciated, the tissueslitting device 2804 may include one or more grinding surfaces 2808 thatcan be linked and/or geared together. For example, in instances wherethe tissue slitting device 2804 includes two or more grinding surfaces2808, the two or more grinding surfaces may be geared to operatesimultaneously. Additionally, the grinding surfaces may be directlygeared and/or indirectly geared to rotate/move in alternate and/orsimilar rotational directions, respectively.

In one embodiment, the grinding surface 2808 may be partially covered bya shielded portion 2820. The shielded portion 2820 may prevent contactof the grinding surface with areas of the vasculature, or lead 104,other than a section of the formed tissue 108 surrounding the lead 104.As can be expected, the partial covering may present an exposed sectionof the grinding surface 2808 to contact the formed tissue that isengaged with the distal tip of the tissue slitting device 2804. In someembodiments, the grinding surface 2808 may be angled, or disposed at anangle, in relation to the distal tip of the tissue slitting device 2804.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a letter thatdistinguishes among the similar components. If only the first referencelabel is used in the specification, the description is applicable to anyone of the similar components having the same first reference labelirrespective of the second reference label.

Presented herein are embodiments of a tissue separating device, system,and method. As described herein, the device(s) may be electrical,mechanical, electro-mechanical, and/or combinations thereof.

Also, while the flowcharts have been discussed and illustrated inrelation to a particular sequence of events, it should be appreciatedthat changes, additions, and omissions to this sequence can occurwithout materially affecting the operation of the disclosed embodiments,configuration, and aspects.

A number of variations and modifications of the disclosure can be used.It would be possible to provide for some features of the disclosurewithout providing others. By way of illustration, any methodology ormodality of cutting tissue may be employed as described herein to effectlead removal from an encased tissue growth.

The present disclosure, in various aspects, embodiments, and/orconfigurations, includes components, methods, processes, systems and/orapparatus substantially as depicted and described herein, includingvarious aspects, embodiments, configurations embodiments,subcombinations, and/or subsets thereof. Those of skill in the art willunderstand how to make and use the disclosed aspects, embodiments,and/or configurations after understanding the present disclosure. Thepresent disclosure, in various aspects, embodiments, and/orconfigurations, includes providing devices and processes in the absenceof items not depicted and/or described herein or in various aspects,embodiments, and/or configurations hereof, including in the absence ofsuch items as may have been used in previous devices or processes, e.g.,for improving performance, achieving ease and/or reducing cost ofimplementation.

The foregoing discussion has been presented for purposes of illustrationand description. The foregoing is not intended to limit the disclosureto the form or forms disclosed herein. In the foregoing Summary forexample, various features of the disclosure are grouped together in oneor more aspects, embodiments, and/or configurations for the purpose ofstreamlining the disclosure. The features of the aspects, embodiments,and/or configurations of the disclosure may be combined in alternateaspects, embodiments, and/or configurations other than those discussedabove. This method of disclosure is not to be interpreted as reflectingan intention that the claims require more features than are expresslyrecited in each claim. Rather, as the following claims reflect,inventive aspects lie in less than all features of a single foregoingdisclosed aspect, embodiment, and/or configuration. Thus, the followingclaims are hereby incorporated into this Summary, with each claimstanding on its own as a separate preferred embodiment of thedisclosure.

Moreover, though the description has included description of one or moreaspects, embodiments, and/or configurations and certain variations andmodifications, other variations, combinations, and modifications arewithin the scope of the disclosure, e.g., as may be within the skill andknowledge of those in the art, after understanding the presentdisclosure. It is intended to obtain rights which include alternativeaspects, embodiments, and/or configurations to the extent permitted,including alternate, interchangeable and/or equivalent structures,functions, ranges or steps to those claimed, whether or not suchalternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

1-47. (canceled)
 48. A tissue-slitting apparatus, comprising: a flexibleshaft including: a proximal portion; a distal portion; and a shaft wallextending between the proximal portion and the distal portion, whereinthe shaft wall defines an inner lumen configured to receive a portion ofa lead at least partially implanted within tissue growth on a vesselwall of a patient; and a transition region disposed at the distalportion of the shaft and including a tapered section, wherein thetapered section projects radially outward from the shaft wall andincludes a cutting surface terminating in a distal tip, wherein thecutting surface is configured to separate the tissue growth from thelead when the portion of the lead is received within the inner lumen tothereby permit the lead to be removed from the patient.
 49. Thetissue-slitting apparatus of claim 48, wherein the shaft furthercomprises a radiopaque marker proximate to the cutting surface.
 50. Thetissue-slitting apparatus of claim 49, wherein the radiopaque markercomprises tantalum, tungsten, carbide, iridium, bismuth oxide, bariumsulfate, cobalt, platinum, or combinations thereof.
 51. Thetissue-slitting apparatus of claim 48, wherein a cross-section of theshaft proximal of the transition region is circular, and wherein across-section of the shaft distal of the transition region isnon-circular.
 52. The tissue-slitting apparatus of claim 51, wherein thetransition region is tapered relative to the circular cross-section. 53.The tissue-slitting apparatus of claim 48, wherein the cutting surfaceis spring-loaded toward the inner lumen.
 54. The tissue-slittingapparatus of claim 48, wherein the tapered section comprises a wedge andthe cutting surface comprises a blade.
 55. The tissue-slitting apparatusof claim 54, wherein the tapered section is configured such that thelead is pushed against the blade when the tissue slitting apparatustraverses along an axial length of the lead.
 56. The tissue-slittingapparatus of claim 55, wherein the wedge is configured to peel thetissue away from the lead when the tissue slitting apparatus traversesalong the axial length of the lead.
 57. The tissue-slitting apparatus ofclaim 54, wherein the blade is formed by an angle of the wedge.
 58. Thetissue-slitting apparatus of claim 48, wherein the cutting surface isdisposed partially within the inner lumen of the shaft.
 59. Thetissue-slitting apparatus of claim 48, further comprising a lead-lockingdevice, traction device, or snare tool configured to pass through theinner lumen of the shaft.
 60. A tissue-slitting method, comprising:providing a flexible shaft including: a proximal portion, a distalportion, and a shaft wall extending between the proximal portion and thedistal portion, wherein the shaft wall defines an inner lumen; and atransition region disposed at the distal portion of the shaft andincluding a tapered section, wherein the tapered section projectsradially outward from the shaft wall and includes a cutting surfaceterminating in a distal tip; and receiving within the inner lumen aportion of a lead at least partially implanted within tissue growth on avessel wall of a patient; advancing the flexible shaft along the lengthof the lead such that the tissue growth is separated from the lead bythe cutting surface; and removing the lead from the patient.
 61. Thetissue-slitting method of claim 60, further comprising tracking alocation of the cutting surface based on a radiopaque marker proximateto the cutting surface.
 62. The tissue-slitting method of claim 60,further comprising separating the tissue growth from the lead with thecutting surface, wherein the cutting surface is spring-loaded toward theinner lumen such that the cutting surface is pressed against the tissuegrowth when the portion of the lead is received within the inner lumen.63. The tissue-slitting method of claim 60, further comprisingseparating the tissue growth from the lead with the tapered section,wherein the tapered section is a wedge.
 64. The tissue-slitting methodof claim 60, further comprising separating the tissue growth from thelead with the cutting surface, wherein the cutting surface is a bladeformed by an angle of the tapered section.
 65. The tissue-slittingmethod of claim 64, further comprising pushing the lead against theblade when the tissue slitting apparatus traverses along an axial lengthof the lead.
 66. The tissue-slitting method of claim 60, furthercomprising, with the tapered section, peeling the tissue away from thelead when the tissue slitting apparatus traverses along an axial lengthof the lead.
 67. The tissue-slitting method of claim 60, furthercomprising separating the tissue growth from the lead with a portion ofthe cutting surface disposed partially within the inner lumen of theshaft.